Elementary 

Forge  Practice 


A  Text-Book 

for 
Technical  and  Vocational  Schools 


By 

ROBERT  H.  HARCOURT 

Instructor  in  Forge  Practice, 
Leland  Stanford  Junior  University 


Second  Edition, 
Enlarged 


MANUAL  ARTS   PRESS 
192^0 


Copyright,  1917,  1920 

by 
Robert  H.  Harcourt 


PREFACE 

to 
SECOND  EDITION 

While  it  is  realized  that  a  comprehensive  knowledge  of  forge 
practice  can  be  gained  only  thru  contact  with  a  commercial 
shop  doing  a  wide  variety  of  work,  it  is  at  the  same  time  be- 
lieved that  an  understanding  of  fundamental  principles  may 
be  secured  thru  a  carefully  planned  and  conducted  course 
of  instruction  in  a  technical  school.  This  book  is  designed 
to  assist  the  student  in  grasping  fundamental  principles.  To 
this  end  a  series  of  projects  involving  fundamental  operations 
has  been  devised. 

It  may  be  unnecessary  for  some  students  to  complete  the 
entire  set.  Some  of  the  earlier  projects  and  occasionally 
others  may  be  omitted  if  the  student  has  had  previous  prac- 
tice or  if  he  shows  great  facility.  On  the  other  hand  it  will 
be  readily  seen  that  there  is  a  logical  order  in  the  series  and 
that  some  projects  must  be  mastered  before  others  are  under- 
taken. 

The  whole  set  may  require  a  longer  time  than  is  allotted 
to  the  subject  in  the  average  manual  training  course.  In  such 
case  the  instructor  may  easily  select  such  work  as  will  meet 
the  peculiar  conditions. 

The  criticism  given  an  earlier  edition  by  the  technical  press, 
and  the  reception  by  teachers  of  forge  and  machine-shop 
practice,  have  shown  the  need  for  a  text-book  of  this  type. 

The  author  wishes  to  express  his  appreciation  of  the  as- 
sistance rendered  by  Professor  E.  P.  Lesley  of  Leland  Stan- 
ford Junior  University,  Mr.  W.  L.  Rifenberick,  and  Mr.  H.  P. 
"Miller,  Jr.,  in  the  preparation  of  this  book. 

R.  H.  HARCOURT. 

Stanford  University,  November,  1919. 


2065907 


CONTENTS 

PAGE 

Chapter  I.     MATERIALS  AND  EQUIPMENT 13 

Materials ;  Wrought  Iron,  Norway  or  Swedish  Iron, 
Machinery  Steel,  High-Carbon  Steel,  High-Speed  Steel; 
Emery-Wheel  Test;  Weight  of  Iron;  Shrinkage;  Bibliog- 
raphy ;  Forge,  Fire  Tools,  Coal,  Building  Fire,  Coke,  Making 
Coke,  Clinker,  Banking  Fire,  Cleaning  Fire  at  End  of 
Period ;  Anvil,  Tool  Rack ;  Hammer,  Backing  Hammer, 
Cross  Peen  Hammer,  Sledges ;  Tongs,  Fitting  Tongs  to  the 
Work;  Measuring  and  Marking  Tools;  Flatter,  Set- 
Hammer,  Chisels,  Grinding  Chisels,  Bob-Punch,  Necking 
Tool,  Fullers,  Swages,  Swage  Block;  Vise,  Cone,  Surface 
Plate,  Shears. 


Chapter   II.    DRAWING-OUT,   BENDING  AND  TWISTING       ...      30 
Oxidizing    Fire;     To  Prevent    the     Formation    of    Scale; 
Welding    Heat,    Indications    of   a   Welding    Heat ;    Burned 
Iron;   Drawing-out,    Squaring,   or  Truing-up,  Work;   Cut- 
ting Cold   Stock,   Cutting  Hot  Stock;  Twisting,   Punching. 

Chapter  III.     COMMON  WELDS 46 

Lap  Weld,  Upsetting,  Scarfing;  Use  of  Fluxes  in  Welding, 
Method  of  Using  Flux;  Welded  Rings;  Forged  Hook, 
Common  Eye-Bolt,  Common  Hinge,  Flat  Ring,  Band  Ring, 
Heading  Tool,  Cupping  Tool,  Bolts. 

Chapter  IV.     SPECIAL  WELDS       .       .       .     . 78 

Butt  Weld,  V-Weld,  Jump  Weld,  Split  Weld,  Split  Weld 
for  Heavy  Stock,  T-Weld,  Angle  Weld. 

Chapter  V.       HAMMER   WORK 86 

Trip-  or  Belt-Hammer,  Steam-Hammer ;  Finishing  Allow- 
ance; Forged  Wrench,  Flat- Jawed  Tongs,  Link  Tongs, 
Hollow-Bit  Tongs. 


CONTENTS 


Chapter  VI.    ANNEALING,  HARDENING  AND  TEMPERING  STEEL      .     101 

Annealing,  Box  Annealing,  Water  Annealing;  Hardening, 
Refining  Heat,  Recalescence,  Tempering,  Guide  for  Hard- 
ening, Tempering  only  the  Cutting  Edges  of  Tools,  Harden- 
ing and  Tempering  Tools  thruout,  Methods  of  Cooling, 
Forging  Heat  of  Tool  Steel,  Heating  Steel  for  Hardening, 
Importance  of  Uniform  Heating,  Hardening  at  a  Rising 
Heat,  Restoring  the  Grain,  Warping  in  Cooling,  Hardening 
Thin  Flat  Articles,  Tempering  Taps,  Tempering  Carving 
Knives,  Tempering  Shear  Blades,  Tempering  Springs,  Case- 
Hardening,  Pack-Hardening;  Treatment  of  High-Speed 
Steel;  Cutting  Stock,  Forging  Heat,  the  Fire,  Heating  for 
Hardening,  Cooling,  Annealing. 

Chapter  VII.    TOOL  FORGING 118 

Selection  of  Steel  for  Tools,  Lathe  Tools,  Cold  Chisel,  Cape 
Chisel,  Round-Nose  Cape  Chisel,  Center-Punch,  Round-Nose 
Tool,  Cutting-off  Tool,  Threading  Tool,  Side  Tool,  Boring 
Tool,  Cross-Peen  Hammer,  Eye-Punch,  Drift-Pin,  Small 
Cross- Peen  Hammer  Ball-Peen  Hammer,  Hot  Eye-Chisel, 
Cold  Eye-Chisel,  Geologist's  Pick,  Hand  Rock-Drill,  Ma- 
chine Rock-Drill,  V-Fullers,  Wing  Swage,  Dolly,  Hunting 
Axe,  Hunting  Knife. 


PROJECTS 


1. 

9 

3. 

Drawing-out   and   Bending   Ring 
S-Hook          

.        .                                    I 
II 
III 

4. 

Beam  Strap  

IV 

5. 

Twisted  Gate-Hook     .... 

.        .                                  V 

6. 

Practice  Welds  —  Fagot 

VI 

7. 

Round  Lap-Weld         .... 

VII 

8. 

Flat   Lap-Weld     ..... 

VIII 

9. 

Links  of    Chain   .        . 

.        .                                IX 

10. 

Ring  —  Round  Lap-Weld 

.        .                                X 

11. 

Ring  —  Link    Scarf       .... 

.        .                                XI 

12. 

Forged    Hook      

XII  and  XIII 

13. 

Common    Eye-Bolt      .... 

.        .                             XIV 

14. 

Common  Hinge   

.        .                              XV 

15. 

Flat    Ring     

.       .                           XVI 

16. 

Band  Ring    

.        .                          XVII 

17. 

Upset-Head   Bolt         .... 

.        .                        XVIII 

18. 

Welded-Head  Bolt      . 

XIX 

19. 

Forged    Bolt         

XIX 

20. 

T-Weld          

XX 

21. 

Angle   Weld         

XXI 

22. 

Forged  Open-End  Wrench 

.      XXII  and  XXIII 

23. 

Flat-Jawed    Tongs       .... 

XXIV  and  XXV 

24. 

Link  Tongs  

.    XXVI  and  XXVII 

25. 

Hollow-Bit  Tongs 

XXVIII 

26. 

Cold  Chisel  

XXIX 

27. 

Cape  Chisel  

.        .                          XXIX 

28. 

Round-Nose  Cape  Chisel    . 

.        .                           XXX 

29. 

Center-Punch        

.        .                           XXX 

30. 

Round-Nose  Tool         .... 

.        .                         XXXI 

31. 

Cutting-Off  Tool          .        .        . 

.        .                          XXXI 

32. 

Threading  Tool   ..... 

XXXII 

33. 

Side  Tool     

XXXIII 

34. 

Boring   Tool         

XXXIV 

35. 

Cross-Peen   Hammer  .... 

XXXV 

36. 

Small  Cross-Peen  Hammer 

XXXVI 

37. 

Ball-Peen    Hammer     .... 

XXXVII 

38. 

Hot  Eye-Chisel     

.        .                   XXXVIII 

39. 

Cold  Eye-Chisel  

XXXIX 

40. 

Geologist's   Pick  ..... 

XL 

41. 

Hand    Rock-Drill 

XLI 

42. 

Machine  Rock-Drill     .... 

XLII 

43. 

XLIII 

44. 

XLIV 

INTRODUCTION 

The  author  has  found  that  very  good  results  may  be  obtained 
by  the  use  of  "Elementary  Forge  Practice"  if  the  following 
methods  are  applied.  Assemble  the  students  and  give  them 
a  talk  and  demonstration  covering  the  following  points : 

1.  The  forge. 

2.  Coal,  coke,  and  clinkers. 

3.  The  anvil. 

4.  Forge  tools,  tongs,  etc. 

5.  Building  the  fire,  banking  fire,  making  coke,  care  of  the 
fire,  etc. 

6.  Materials :     Tool   steel,  machinery   steel,  and   wrought 
iron.    Their  characteristics   and  the  methods  for  distinguishing 
them. 

7.  A  piece  of  machinery  steel  ^  or  Y^  of  an  inch  in  diam- 
eter should  be  heated  and  drawn  out  as  described  on  page  32. 
Only  a  portion   of  the  stock  necessary  to  make  the  project 
is  drawn  out.    The  next  step  is  to  take  a  piece  of  stock  ^  an 
inch  in  diameter  and   11  jA  inches  long.     This  is  heated  and 
bent  as  described  on  page  36. 

A  piece  of  stock  }i  or  y^  an  inch  in  diameter  is  pointed. 
A  wedge  for  a  hand-hammer  is  also  made.  This  completes 
the  first  demonstration. 

A  demonstration  should  not  be  necessary  for  projects  2 
and  3. 

Experience  has  shown  that  where  the  first  demonstration 
and  explanations  have  been  thoro,  fewer  demonstrations  are 
required. 

Demonstrations  are  given  only  when  they  are  absolutely 
necessary.  The 'difficult  projects  such  as  the  Lap-weld,  Link, 
Hook,  Tongs,  and  a  few  others  require  them. 


10  INTRODUCTION 

Toward  the  end  of  the  term,  talks  and  demonstrations  are 
given  covering  the  making  of  crank  shafts,  drop  forgings, 
special  welds,  and  manufacturing  methods. 

Upon  completion  oi  the  required  number  of  projects,  or 
work  accepted  in  lieu  of  them,  students  are  encouraged  to 
make  hunting  knives,  axes,  or  work  which  has  a  special 
interest  for  them. 

Written  examinations  including  questions  of  the  following 
type  are  given  about  once  a  month : 

1.  Give  a  method  for  distinguishing  wrought  iron  from 
machinery  steel. 

2.  What  percentage   of   carbon  do  tool   steel,  machinery 
steel,   and   wrought   iron   contain? 

3.  Why  is  a  'flux  used  when  welding  steel? 

4.  What  is  an  oxidizing  fire? 

5.  Give  a  method  for  finding  the  refining  or  hardening 
heat  for  tool  steel. 

6.  What  is  the  purpose  of  pack  hardening? 

7.  Why  is  tool  steel  annealed? 

8.  Describe  the  process  of  water-annealing  tool  steel. 

9.  Describe  one  method  of  tempering  a  spring. 

10.  How  is  a  cold  chisel  hardened  and  tempered? 

11.  What  is  the  length  of  stock  necessary  for  a  ring  of 
one-inch  round  iron,  having  an  inside  diameter  of  ten  inches, 
allowing  y?  an  inch  for  upset  and  waste  in  welding? 

12.  How  is  high-speed  steel  hardened? 

13.  Describe  one  method  of  hardening  and  tempering  a 
tap. 

14.  Draw  a  diagram  of  an  anvil,  designate  the  parts  and 
give  the  material  of  which  they  are  made. 

15.  What  is  meant  by  drawing  the  temper? 

The  use  of  this  book  has  clearly  demonstrated  the  following 
advantages : 


INTRODUCTION  11 

1.  Taking  of   notes   during   a   demonstration   is   partially 
eliminated,  so  that  a  student  has  the  fullest  opportunity  for 
watching  the  entire  demonstration.     The  text  is  a  ready  ref- 
erence in  case  he  does  not  remember  a  demonstrated  point. 

2.  Students  do  better  work  and  complete  the  projects  in 
a  shorter  period  of  time. 

3.  Students  are  able  to  proceed  with  the  projects  without 
personal  instruction.     This  eliminates  a  great  waste  of  time. 

4.  The   instructor  is   able  to   handle  a  large  number  of 
students  efficiently  and  without  confusion. 

5.  It  develops  initiative,  eliminates  idleness  and  promotes 
efficiency  and  discipline. 

NOTE — The  best  results  will  be  obtained  if  the  student  uses 
the  book  as  a  guide  while  at  work. 


Elementary  Forge  Practice 


CHAPTER  I. 
MATERIALS  AND  EQUIPMENT. 

The  Materials  most  commonly  used  in  forging  are : 
wrought  iron,  Norway  iron,  machine  steel,  tool  steel,  and  high- 
speed steel.  Their  main  constituent  is  iron,  as  obtained  from 
iron  ore ;  but  they  differ  in  the  amount  of  carbon  and  other 
elements  that  are  mixed  or  alloyed  with  the  iron. 

Wrought  Iron  is  made  by  the  Puddling  Process,  and  dif- 
fers from  other  kinds  of  iron  mainly  because  of  the  slag  seams 
introduced  during  its  manufacture.  These  seams  cause  the 
stringy,  fibrous  appearance  of  the  iron  when  it  is  broken  or 
cut  cold.  They  are  helpful  when  welding,  since  the  slag  acts 
as  a  flux ;  but  they  also  weaken  the  iron,  and  make  it  liable 
to  crack.  '  Wrought  iron  is  much  easier  to  weld  than  machine 
steel,  because  the  range  of  temperature  thru  which  it  may 
be  heated  without  injury  is  much  greater.  It  may  not  be 
hardened  to  any  appreciable  extent.  If  hammered  too  much 
when  cold  it  will  burst  thru  the  slag  seams. 

The  percentage  of  carbon  in  common  wrought  iron  is  very 
low,  being  about  .04%. 

Norway  or  Swedish  Iron,  as  imported  from  Norway  and 
Sweden,  is  made  in  a  charcoal  furnace.  It  is  the  purest  soft 
iron  on  the  market,  as  the  ore  from  which  it  is  made  is  prac- 
tically free  from  phosphorus  and  sulphur.  It  is  used  mainly 
for  intricate  work  involving  much  bending  and,  since  it  rusts 
very  slowly,  for  forgings  that  are  exposed  to  the  weather. 
The  best  grades  of  crucible  steel  produced  in  this  country  are 
also  made  from  this  kind  of  iron. 

13 


14  MATERIALS    AND   EQUIPMENT 

Machinery  Steel,  also  known  as  machine  steel,  low-carbon 
steel,  and  mild  steel,  contains  from  about  .05%  to  .5%  of 
carbon,  and  is  made  by  the  Open-Hearth  or  Bessemer  Process. 
It  may  be  easily  welded  with  the  aid  of  a  flux,  and  can  be 
welded  without  one.  Being  stronger,  more  homogeneous  and 
cheaper  than  wrought  iron,  it  is  well  adapted  for  forgings.  It 
cannot  be  hardened  to  any  very  great  extent.  A  piece  of  good 
grade  24-inch  thick  may  be  bent  cold  180°  flat  on  itself  with- 
out rupture.  In  general  it  is  found  that  increasing  the  carbon 
content  will  increase  the  strength,  elasticity  and  hardening 
quality,  and  decrease  the  ductility  and  weldability. 

This  grade  of  steel  differs  from  wrought  iron  in  that  it 
does  not  become  soft  and  plastic  at  the  welding  heat.  It 
burns  or  wastes  away  at  a  lower  temperature  than  wrought 
iron,  making  it  "more  difficult  to  weld.  The  crystalline,  or 
granular,  appearance  of  the  fracture,  the  absence  of  slag 
seams,  and  the  emery-wheel  test  described  later,  are  used  to 
distinguish  it  from  wrought  iron. 

High-Carbon  Steel,  or  tool  steel,  the  best  grades  of  which 
are  made  by  the  Crucible  Process,  contains  carbon  in  amounts 
varying  from  .5%  to  1.6%.  Steel  with  a  higher  carbon  con- 
tent is  seldom  used.  High-carbon  steel  is  generally  dis- 
tinguished from  low-carbon  steel  by  the  fact  that  it  becomes 
very  hard  when  heated  to  a  red  heat  and  suddenly  cooled.  It 
snaps  off  when  cut  cold,  on  account  of  the  hardness  of  the 
ordinary  commercial  stock.  As  with  mild,  or  low-carbon  steel, 
the  hardening  quality  varies  directly  with  the  carbon  content. 
There  are,  however,  some  brands  of  steel  containing  less  than 
.5%  carbon  which  harden  considerably  when  heated  and  cooled 
quickly;  so  there  is  no  well  marked  division  between  the  two 
classes.  High-carbon  steel  is  most  difficult  to  weld. 

High-Speed  Steel  is  of  special  importance  in  the  machine 
shop  on  account  of  its  red  hardness,  or  property  of  retaining 
a  cutting  edge  at  a  visible  red  heat.  Tools  made  from  ordi- 
nary high-carbon  steel,  if  heated  by  friction  or  otherwise  to  a 


IRON  AND  STEEL  15 

temperature  of  about  400°  F.,  begin  to  lose  their  hardness ; 
while  high-speed  steel  tools  may  be  heated  up  to  about  1200° 
F.  before  they  break  down  from  softening. 

This  property  is  due  to  the  presence  in  the  steel  of  from 
13%  to  19%  tungsten.  Other  elements  are  present  in  approx- 
imately the  percentages  given : 

Tungsten        Chromium        Carbon       Manganese        Vanadium       Silicon 
16.87  2.99  0.65  0.31  0.85  0.27 

The  Emery-Wheel  Test. — The  most  satisfactory  shop 
method  for  distinguishing  between  the  different  kinds  and 
grades  of  iron  and  steel  consists  in  observing  the  sparks 
given  off  when  a  bar  of  the  material  is  brought  in  contact 
with  a  rapidly  revolving  emery-wheel.  In  general  it  is  found 
that  the  more  carbon  there  is  present  the  brighter  the  sparks 
will  be. 

Sparks  obtained  from  wrought  iron  are  light-straw  color, 
and  follow  straight  lines.  Machine  steel  gives  off  sparks 
that  are  much  the  same  in  character  except  that  they  explode, 
or  fork,  to  some  extent.  White  sparks  which  explode  much 
more  frequently  are  obtained  from  high-carbon  steel.  Those 
given  off  by  high-speed  steel  follow  straight  lines,  similarly 
to  sparks  from  wrought  iron,  but  give  off  much  less  light,  and 
end  abruptly  in  a  chrome-yellow,  pear-shaped  flame. 

Weight  of  Iron. — It  is  often  necessary  to  know  the 
weight  of  material  used  in  an  iron  or  steel  forging.  This  can 
be  computed  if  it  is  remembered  that  a  cubic  foot  of  steel 
weighs  about  490  pounds,  or  that  a  1-inch  square  bar  1  foot 
long  weighs  3.40  pounds  and  a  1-inch  round  bar  of  the  same 
length  weighs  2.67  pounds. 

Shrinkage. — When  iron  or  steel  is  heated,  it  expands  in 
direct  proportion  to  the  change  in  temperature.  A  bar  heated 
to  a  good  forging  heat  will  have  each  of  its  linear  dimensions 
increased  about  %  inch  to  the  foot.  Upon  cooling  it  will  con- 
tract about  the  same  amount. 


16  MATERIALS    AND    EQUIPMENT 

Bibliography. — For  a  complete  description  of  the  various 
processes  employed  in  making  iron  and  steel,  the  student  is 
referred  to  the  following  books: 

Stoughton:     The    Metallurgy    of    Iron    and    Steel.      McGraw-Hill 

Book  Co.,  New  York. 
Metcalf:  Steel.    John  Wiley  &  Sons,  New  York. 

Forge. — One  of  the  commonest  types  of  forge  used  in 
universities  and  technical  schools  is  shown  in  Fig.  1.  It  con- 
sists of  a  cast-iron  hearth  (A)  mounted  on  a  suitable  base 
(//)  and  having  at  its  center  a  fire-pot  (5).  This  fire-pot 
is  made  in  various  shapes  and  sizes,  and  is  sometimes  lined 
with  firebrick.  At  the  bottom  of  the  fire-pot  is  an  opening, 


Fig.  1.     THE  FORGE. 

A,   hearth;    B,   fire-pot;    C,   tuyere  lever;    D,   blast-gate    lever;    E, 

adjustable  hood;   F,   adjusting  lever;  G,   exhaust   pipe;   H,   base;   /. 
coal-box ;  /,  coke-box. 


FIRE  17 

called  the  tuyere,  thru  which  the  blast  is  forced.  Tuyeres  are 
constructed  so  as  to  admit  the  air  readily  and  at  the  same  time 
prevent  coal  from  dropping  thru  them.  Some  are  arranged 
so  that  the  coal  and  ashes  which  do  drop  thru  can  be  shaken 
out  by  means  of  the  tuyere  lever  (C).  The  air  blast  is  con- 
trolled by  means  of  the  blast-gate  lever  (D). 

The  forge  shown  is  of  the  down-draft  type,  the  smoke  and 
gases  from  the  fire  being  drawn  under  the  adjustable  hood 
(E)  and  down  thru  the  exhaust  pipe  (G).  The  position  of 
the  hood  can  be  changed  by  means  of  the  adjusting  lever  (F}. 
The  boxes  (/)  and  (/)  should  be  used  for  holding  coal  and 
coke  respectively,  a  separate  tank  for  water  being  advisable. 

In  commercial  shops  the  forges  are  generally  circular  and 
made  of  light  sheet  steel. 

Fire  Tools. — The  tools  required  at  each  forge  in  order  to 
take  proper  care  of  the  fire  are :  coal  shovel,  fire  rake,  dipper, 
and  poker. 

Coal. — The  best  "blacksmith's"  coal  for  use  in  a  forge  is 
a  high  grade  of  soft  or  bituminous  coal.  It  can  in  general  be 
distinguished  by  the  crumbling  of  the  lumps  when  hit  with  a 
hammer,  but  the  most  reliable  test  is  to  note  its  characteris- 
tics in  actual  use.  When  dampened  and  put  on  a  fire  it  should 
cake  up,  forming  good  coke  and  leaving  very  little  clinker 
when  burned.  Ordinary  soft  coal,  or  steam-coal,  makes  a  very 
dirty  fire,  giving  off  much  smoke  and  leaving  a  great  deal  of 
clinker.  It  is  very  disagreeable  to  work  with,  on  account  both 
of  the  smoke  and  the  hot  gases  given  off. 

Coal  containing  either  sulphur  or  phosphorus  is  to  be 
avoided,  as  these  elements  are  absorbed  by  the  iron.  Sulphur 
makes  the  iron  hot-short,  i.  e.,  brittle  while  hot ;  and  phos- 
phorus makes  it  cold-short,  or  brittle  when  cold. 

Building  Fire. — The  success  of  welding  and  forging  de- 
pends, to  a  large  extent,  on  the  building  and  care  of  the  fire. 
When  a  fresh  fire  is  to  be  built,  make  a  hole  about  8  inches  in 
diameter  at  the  center  of  the  hearth,  removing  enough  of  the 


18  MATERIALS    AND    EQUIPMENT 

dirt  and  ashes  to  expose  the  tuyere.  Place  some  shavings  in 
this  hole  and  on  top  of  them  some  small  lumps  of  coke.  After 
lighting  the  shavings,  turn  the  blast  on  a  little  and  wait  until 
the  coke  has  become  red  hot.  More  coke  should  then  be 
added,  forming  a  cone,  and  the  space  around  it  banked,  or 
filled  in,  with  moist  coal.  Care  must  be  taken  in  dampening 
the  coal  not  to  get  it  too  wet,  or  the  water  will  seep  out  and  run 
over  the  tuyere,  thereby  spoiling  the  fire.  When  enough  coal 
has  been  placed  around  the  fire,  it  should  be  leveled  off  and 
packed  down  hard  with  the  back  of  a  shovel.  This  is  done  to 
prevent  the  air-blast  from  coming  thru  at  the  outer  edges  of 
the  fire,  spreading  it  over  too  large  an  area. 

Coke. — It  is  found  that  packing  also  helps  materially  in 
the  production  of  coke,  which  is  formed  by  the  caking  of  the 
coal  after  the  fire  has  burned  for  some  time.  Coke  should  be 
saved  when  cleaning  out  the  fire  or  hearth  at  the  end  of  a 
period,  or  when  building  a  second  fire.  The  center  of  the 
fire  burns  out  somewhat  like  a  crater,  and  has  to  be  constantly 
refilled  with  extra  coke.  If  it  is  necessary  to  have  a  small 
fire,  the  coke  should  be  broken  into  small  pieces. 

Making  Coke. — When  extra  coke  is  required,  it  can  be 
made  by  placing  some  large  lumps,  or  wet  coal,  on  top  of  the 
fire  and  allowing  it  to  burn  slowly  for  some  time.  It  should 
not  be  disturbed  with  a  poker  until  it  has  caked  well. 

Caution. — Do  not  continually  poke  or  disturb  the  fire,  but 
keep  the  center  full  of  small  pieces  of  coke. 

Clinker. — Dirt  and  dross  in  the  coal  form  clinker  directly 
above  the  tuyere.  This  is  a  detriment  when  welding,  since  it 
prevents  air  from  coming  thru  the  tuyere  and  causes  a  de- 
posit of  dirt  on  the  pieces  in  the  fire.  For  this  reason  the  fire 
should  be  cleaned  out  every  half-hour,  when  welding,  by  re- 
-  moving  the  clinker  with  a  poker.  Care  must  be  taken  to  pre- 
vent lead  and  babbitt  metal  from  getting  into  the  fire,  as  they 
oxidize  and  prevent  welding. 


FIRE 


19 


Banking  Fire. — By  placing  a  piece  of  -wood  on  end  in  the 
fire  and  covering  it  with  coke  and  coal,  the  fire  will  last  for 
some  time  without  air-blast. 

Cleaning  Fire  at  End  of  Period. — When  the  fire  is  no 
longer  needed,  the  coal  should  be  removed  and  placed  in  the 
coal-tank.  The  coke  should  then  be  loosened  with  the  poker, 
moistened  with  water,  and  placed  in  the  coke-tank.  The 
clinker  and  ashes  are  dug  out  and  thrown  into  the  ash-box. 
The  forge  is  then  clean  and  ready  for  future  use. 


Fig.  2.     THE  ANVIL. 

A,  body ;   B,  horn ;   C,  base  of  horn ;   D,   face ;   E,  hardie  hole ;   F, 
pritchel   hole ;   G,   rounded  edges. 

Anvil. — The  type  of  anvil  generally  used  is  shown  in  Pig. 
2.  The  body  (A)  is  usually  made  of  wrought  iron  or  a  special 
grade  of  steel,  but  for  light  work  it  is  sometimes  of  cast  iron. 
The  horn  (B)  must  be  tough  in  order  to  withstand  heavy 
pounding  and  is  usually  of  the  same  material  as  the  body. 
The  base  of  the  horn  (C)  has  a  flat  top  which  is  used  in  pref- 
erence to  the  face  when  cutting  stock  with  a  chisel,  because 


20  MATERIALS  AND  EQUIPMENT 

it  is  not  so  hard  and  will  not  dull  the  chisel.  The  face  (£>) 
is  a  tool-steel  plate  ^ -inch  thick  which  is  welded  to  the  body. 
It  is  carefully  hardened  and  has  a  smoothly  ground  top.  The 
square  hardie  hole  (£)  is  used  for  holding  the  shanks  of 
tools,  while  the  pritchel  hole  (F)  is  very  convenient  in  making 
small  bolts,  as  it  allows  their  stems,  or  shanks,  to  extend  thru. 
The  two  side  edges  of  the  face  (G)  are  rounded  for  about  4 
inches  near  the  horn,  to  facilitate  the  bending  of  stock.  If  in- 
tended for  small  work,  like  the  projects  in  this  book,  an  anvil 
should  weigh  about  150  pounds. 

The  anvil  should  be  placed  with  the  horn  at  the  left  of  the 
worker  and  the  face  26  inches  above  the  floor,  the  outer  edge 
being  about  %  inch  lower  than  the  inner  one.  It  is  therefore 
necessary  to  provide  a  base.  This  is  generally  of  cast  iron,  as 
shown  in  Fig.  2,  but  may  consist  of  a  large  wooden  block. 


Fig.  3.     TOOL-RACK. 

Tool-Rack. — To  have  the  blacksmith  tools  within  easy 
reach  while  working  at  the  forge,  they  should  be  kept  on  some 
sort  of  a  tool-rack.  A  very  good  type  is  shown  in  Fig.  3. 
It  consists  of  an  iron  top  cast  on  one  end  of  a  piece  of  large 
pipe.  The  other  end  of  the  pipe  is  imbedded  in  the  floor. 
Slots  for  holding  tools  are  provided  on  each  side  of  the  top, 
which  acts  as  a  table  for  pieces  of  stock,  supplies,  etc. 


21 


These  racks  are  sometimes  made  of  wood,  but  such  are 
easily  burned  by  hot  materials,  and,  since  they  usually  have 
four  legs  and  a  bottom  shelf,  it  is  rather  hard  to  clean  under 
them. 

The  Hammer  used  most  commonly  by  blacksmiths  is  a 
ball-peen  hammer  weighing  from  1^2  to  2^  pounds  and  sim- 
ilar to  the  one  shown  in  Fig.  4.  The  face,  or  large  end,  is  for 
ordinary  work ;  and  the  ball  end,  or  peen,  for  scarfing,  rivet- 
ing, etc.  The  face  should  be  convex,  in  order  not  to  mark 
hot  material,  and  its  edges  rounded  off,  to  keep  them  from 
breaking.  The  edge  of  the  face  nearest  the  worker  is  called 
the  heel,  and  the  front  edge  the  toe. 


Fig.  4. 

HAND-HAMMER. 


Fig.  5. 
CROSS-PEEN. 


A  Backing  Hammer  generally  has  the  same  shape  as  the 
common  ball  peen  hammer,  but  it  weighs  about  5  pounds. 
It  is  used  by  a  helper  when  light  quick  blows  are  necessary, 
and  also  when  backing  up,  or  starting,  the  heel  of  a  scarf. 

A  Cross-peen  Hammer,  Fig.  5,  weighing  about  3^ 
pounds,  is  needed  for  each  two  forges.  This  hammer  is  par- 
ticularly valuable  in  welding  steel  on  account  of  the  heavier 
blows  which  can  be  delivered.  It  is  also  useful  when  making 
a  pair  of  tongs,  and  in  almost  any  work  where  one  student 
needs  the  help  of  another. 

Sledges. — Fig.  6  shows  a  sledge  of  the  straight-peen  type, 


22 


MATERIALS   AND   EQUIPMENT 


which  is  ordinarily  used  in  a  blacksmith  shop.    The  weight  of 
such  sledges  varies  from  8  to  13  pounds. 

Tongs  vary  in  form,  depending  on  the  size  and  shape  of 
the  stock  handled.  Those  frequently  used  in  the  forge  shop 
are  shown  in  Fig.  7. 


E 

Fig.  7. 
A,  flat-jawed;  B,  hollow-bits;  C,  link;  D,  pick-ups;  E,  chisel. 

The  Flat-Jawed  Tongs,  shown  at  A  in  Fig.  7,  are  used  for 
holding  flat  stock. 

The  Hollow-Bit  Tongs  (B,  Fig.  7)  are  employed  in 
handling  round,  square,  or  flat  material. 


TONGS  23 

Link  Tongs  are  shown  at  C,  Fig.  7,  and  are  very  con- 
venient for  holding  links  or  rings. 

Pick-up  Tongs  (D,  Fig.  7)  are  intended  mainly  for  pick- 
ing up  large  and  small  pieces  of  different  sizes  of  stock. 

The  Eye  Tongs,  or  eye-chisel  tongs,  shown  at  E  in  Fig.  7, 
are  used  in  dressing  an  eye-chisel.  The  projections  are  made 
to  fit  into  the  eye,  while  the  jaws  are  bent  so  as  to  avoid  con- 
tact with  the  burred  head  of  the  chisel. 

Fitting  Tongs  to  the  Work. — Tongs  should  always  be 
fitted  to  the  work  which  they  are  intended  to  hold.  The 
poorly  fitted  tongs  shown  at  A,  Fig.  8,  should  be  changed  so 
that  the  jaws  touch  the  stock  for  their  entire  length,  as  in  B, 
Fig.  8.  Their  form  at  A  affords  a  poor  grip,  which  is  a  seri- 
ous drawback  when  forging  or  welding. 


To  fit  tongs  to  a  piece  of  work  the  jaws  should  be  heated 
red  hot,  the  stock  placed  between  them,  and  the  jaws  ham- 
mered down  tight  around  it.  In  order  to  prevent  the  handles, 
or  reins,  from  coming  too  close  together  while  doing  this,  a 
piece  of  iron  should  be  placed  between  them  directly  behind 
the  jaws.  If  the  handles  are  too  far  apart,  give  them  several 
blows  a  short  distance  back  of  the  eye. 

Never  leave  tongs  on  a  piece  of  work  while  it  is  in  the  fire 
if  there  is  danger  of  their  becoming  hot.  When  removed 
from  the  fire  they  will  .not  hold  the  work  firmly,  because  the 
handles  will  come  together  under  the  pressure  of  the  hand. 


24 


MATERIALS    AND    EQUIPMENT 


Measuring  and  Marking  Tools. — In  forging  it  is  often 
required  to  work  to  a  given  size,  or  to  duplicate  another 
forging.  For  this  reason  it  is  necessary  to  have  on  hand  a 
rule,  a  pair  of  calipers,  and  a  try-square,  as  shown  in  Fig.  9. 


Center  Punches 


Fig.  9.     MEASURING  AND  MARKING  TOOLS. 

The  rule  should  be  of  brass  in  order  to  withstand  the  heat,  and 
should  have  a  12-inch  scale  with  enough  extra  room  for  a 
hand-hold.  The  calipers  are  generally  made  of  steel,  and  are 
used  mainly  for  work  done  under  the  trip-hammer.  The  try- 
square  need  only  be  a  small  one. 

For  marking  stock  a  center-punch  is  generally  employed, 


Fig.  10.    THK  FLATTER.          Fig.  11.    THE  SET-HAMMER. 

since  the  mark  made  by  a  chisel  will  start  a  crack  if  the  stock 
is  bent.  A  chisel  should  be  used  only  when  the  stock  is  to  be 
cut  off  at  the  point  marked. 

The  Flatter,  Fig.  10,  is  used  for  flattening  and  smoothing 


25 


straight  surfaces.  Its  face  is  generally  about  3  inches  square, 
and  should  be  smooth  with  rounded  edges. 

The  Set-Hammer,  shown  in  Fig.  11,  is  used  in  finishing 
corners  and  parts  that  cannot  be  reached  with  the  flatter. 
The  sizes  vary,  but  for  small  work  the  face  should  be  about 
\Y4  inches  square.  It  also  should  be  smooth  and  flat.  The  one 
illustrated  is  commonly  called  the  square-edge  set-hammer,  to 
distinguish  it  from  the  round-edge  set-hammer. 

Chisels. — Two  kinds  of  chisels  are  commonly  used  in  the 
forge  shop :  one  for  cutting  cold  material,  and  the  other  for 
cutting  hot  material.  These  are  called  cold  and  hot  chisels. 

The  cold  chisel,  Fig.  12,  is  made  thicker  in  the  blade  than 
the  hot  chisel,  Fig.  13,  which  has  a  rather  thin  edge.  The 


Fig.  12. 
COLD  CHISEL. 


Fig.  13. 
HOT  CHISEL 


Fig.  14. 
HARDIE. 


hardie,  shown  in  Fig.  14,  is  used  for  cutting  hot  material.  It 
has  a  square  shank  to  fit  the  hardie  hole  in  the  anvil.  Hardies 
are  also  made  to  cut  cold  stock. 

The  hot  chisel  should  never  be  used  on  cold  material,  as 
its  edge  will  be  turned  and  ruined;  nor  should  the  cold  chisel 
be  used  for  cutting  hot  stock,  as  the  heat  will  soften  its  edge, 
making  it  unfit  for  cutting  cold  stock. 

Grinding  Chisels. — The  sides  of  a  cold  chisel  should  be 
ground  to  an  angle  of  about  60  degrees  with  each  other,  as 
shown  at  A  in  Fig.  15.  This  forms  a  good  cutting  edge.  If 
the  edge  is  too  thin  it  will  bend. 


26 


MATERIALS    AND    EQUIPMENT 


The  cutting  edge  should  also  be  .ground  convex,  as  shown 
slightly  exaggerated  at  B.  This  prevents  the  corners  from 
breaking  off  too  readily,  as  they  would  if  it  were  ground  as 
at  C. 

Hot  chisels  are  ground  somewhat  thinner  than  cold  chisels, 
and  with  the  sides  at  an  angle  of  about  30°. 


Fig.  15. 

The  Bob-Punch,  shown  in  Fig.  16,  is  used  in  place  of  the 
peen  of  a  hammer  for  hollowing  out  stock.  Examples  of  its 
application  are  given  in  several  of  the  special  welds  described 
in  Chapter  IV.  It  is  hit  with  a  heavy  hammer,  in  the  same 
manner  as  the  flatter.  If  a  hand  hammer  were  used  in  place 
of  the  bob-punch  its  hardened  face  might  break  when  struck. 


Fig.  16. 
BOB-PUNCH. 


Fig.  17. 
NECKING  TOOL. 


Necking  Tool. — In  certain  cases,  such  as  welding  an  eye- 
bolt,  finishing  the  inside  of  the  eye  of  a  forged  hook,  and 
making  a  T-weld,  a  necking  tool  (Fig.  17)  is  very  convenient, 
but  not  absolutely  necessary. 

Fullers. — Fig.  18  shows  top  and  bottom  fullers,  which  are 


FULLERS  AND  SWAGES 


27 


used  in  forming  grooves  and  filleted  corners.  They  are  made 
in  a  number  of  sizes,  depending  upon  the  radius  of  the  cir- 
cular edge.  On  a  24-inch  fuller  this  radius  would  be  ^  inch. 
The  top  fuller,  A,  is  made  with  a  handle,  while  the  bottom 
fuller,  B,  has  a  square  shank,  like  the  hardie. 


Fig.  18 
TOP  AND  BOTTOM  FULLER. 


Fig.  19. 
TOP  AND  BOTTOM  SWAGE. 


Swages. —  A  top  and  a  bottom  swage  are  shown  at  A  and  B 
in  Fig.  19.  They  are  used  for  a  wide  variety  of  purposes,  but 
mainly  for  finishing  round  material.  The  sizes  vary  accord- 


Fig.  20.    THE  SWAGE  BLOCK. 


ing  to  the  diameter  of  the  round  stock  for  which  they  are 
made.    Thus  a  2-inch  swage  is  used  on  2-inch  round  stock. 


28 


MATERIALS    AND   EQUIPMENT 


A  Swage  Block  is  shown  in  Fig.  20.  These  blocks  are 
usually  made  of  cast  iron,  and,  owing  to  their  wide  range  of 
utility,  in  various  shapes  and  sizei.  They  are  of  special  im- 
portance in  small  shops,  as  they  can  be  made  to  take  the  place 
of  numerous  swages  and  special  tools.  A  .cast-iron  base  is 
generally  provided,  as  shown,  on  which  they  can  be  placed 
in  either  a  flat  or  an  upright  position. 

Vise. — For  work  requiring  twisting  and  riling,  some  kind 
of  a  vise  is  desirable.  The  type  most  commonly  used  in  a 
forge  shop  is  shown  in  Fig.  21.  A  vise  should  always  be  at- 
tached to  a  firm  and  substantial  bench. 


Fig.  21.     THE  VISE.  Fig.  22.     THE  CONE. 

The  Cone,  Fig.  22,  is  used  for  rounding,  or  truing,  rings. 
This  is  done  by  heating  the  rings  thruout  and  forcing  them 
down  on  the  cone.  If  the  ring  is  made  in  the  form  of  a  band 
from  flat  stock,  it  must  be  turned  over  and  both  edges  ex- 
panded equally  to  make  it  straight. 

Cones  are  made  of  cast  iron  in  various  sizes.  A  conveni- 
ent one  is  from  2^  to  Zl/2  feet  high,  with  the  diameter  of 
the  small  end  2  inches  and  of  the  large  end  about  14  inches. 


SURFACE  PLATE 


29 


The  Surface  Plate  suitable  for  technical  schools  is  made  of 
cast  iron,  and  is  about  2  by  3  feet,  varying  in  thickness  from 
2  to  4  inches.  It  should  have  a  number  of  l)4"mch  round  or 
square  holes  in  it,  spaced  about  3  inches  between  centers. 


Fig.  23.     THE  SURFACE  PLATE. 

These  are  used  for  holding  pins  and  formers  when  bending 
rings,  pipes,  and  work  similar  in  character.  The  face  of  the 
plate  should  be  planed,  so  that  work  can,  be  straightened  or 
tested  on  it. 

These  plates  are  usually  mounted  on  cast  iron  bases,  as 
shown  in  Fig.  23 ;  but  wooden  blocks  may  be  used. 

Shears. — For  cutting  off  cold  stock,  shears  are  generally 
used  in  preference  to  a  hardie  or  chisel,  on  account  of  the 
time  which  may  be  saved.  They  are  either  hand-  or  power- 
operated,  and  vary  in  size,  being  usually  designated  by  the 
maximum  size  of  stock  which  can  be  cut.  One  that  should 
meet  most  of  the  demands  of  a  technical  school  will  cut 
24  x  4  inch  stock.  When  material  is  cut  with  the  shears,  its 
ends  are  rough  and  have  to  be  squared  up  on  the  anvil. 


CHAPTER  II. 
DRAWING-OUT,  BENDING  AND  TWISTING. 

Oxidizing  Fire. — As  the  coal  in  a  forge  burns  it  con- 
sumes oxygen  from  the  air-blast.  If  too  much  air  is  blown 
thru  the  fire  there  will  be  an  excess  of  oxygen.  This  will  at- 
tack the  heated  iron  or  steel,  forming  scale,  or  oxide  of  iron. 
The  rate  of  this  scale  formation  increases  with  the  rise  in 
temperature  of  the  material. 

Scale  should  be  avoided  even  on  an  ordinary  forging,  since 
it  pits  the  material  and,  if  not  removed  while  hot,  makes  it 
look  as  though  it  had  been  overheated.  Unless  the  scale  is 
in  a  molten  condition  it  is  also  impossible  to  make  a  sound 
weld. 

To  Prevent  the  Formation  of  Scale  the  following  precau- 
tions should  be  taken : 

1.  Have  a  good  bed  of  hot  coals  over  the  tuyere  iron  for 
the  air  to  pass  thru. 

2.  Keep  the  material  well  covered  with  coke,  in  order  to 
make  the  part  of  its  surface  exposed  to  the  air  as  small  as 
possible.     If  the  air-blast  comes  in  direct  contact  with  the 
material,  scale  will  form  and  the  material  will  be  cooled  to  a 
certain  extent. 

3.  Do  not  put  on  too  much  blast,  i.  e.,  force  too  much  air 
thru  the  fire.    If  this  is  done  the  hot  coals  will  be  blown  out 
of  the  center  of  the  fire,  leaving  no  bed  of  hot  coals  for  con- 
suming the  oxygen. 

Welding  Heat. — When  pieces  of  wrought  iron  are  heated 
they  soften,  until  at  a  certain  temperature  they  will  stick  to- 
gether if  placed  in  contact.  The  temperature  at  which  this 
soft  and  sticky  condition  occurs  is  known  as  the  welding  heat 
of  wrought  iron. 

Soft   steel   has   the   required   welding   characteristics   at   a 

30 


WELDING  HEAT  31 

lower  temperature  than  wrought  iron.     It  does  not,  however, 
become  very  soft  at  this  heat. 

Indications  of  a  Welding  Heat. — Just  before  the  iron 
reaches  the  welding  heat,  explosive  sparks  will  fly  out  of  the 
fire.  These  sparks  are  small  particles  of  the  material  which 
have  melted  off  and  are  being  blown  out. 

To  reach  this  condition  and  have  the  material  of  uniform 
temperature  thruout,  the  heating  must  be  done  slowly.  If  too 
much  air-blast  is  used  the  outside  of  the  material  will  burn 
as  just  described,  but  the  center  will  remain  hard.  An  attempt 
to  weld  two  pieces  heated  in  this  manner  will  generally  result 
in  a  failure,  since  the  cold  inside  together  with  the  surround- 
ing air  will  quickly  cool  the  outside  surface. 

Burned  Iron. — If  a  bar  of  wrought  iron,  or  mild  steel,  be 
allowed  to  remain  in  the  fire  with  the  blast  on  after  the  weld- 
ing heat  has  been  reached,  it  will  burn.  The  material  which 
is  burned  off  runs  over  the  tuyere  and  forms  lumps  similar  to 
the  clinker.  Since  the  burned  portion  of  an  iron  bar  is  ab- 
solutely useless,  care  should  be  taken  to  remove  the  bar  when 
it  has  reached  the  welding  heat. 

The  air-blast  should  always  be  turned  off  when  the  mate- 
rial is  removed  from  the  fire.  This  prevents  a  waste  of  coal 
and  keeps  the  fire  small. 

Drawing-Out  is  the  process  of  increasing  the  length  of  a 
piece  of  stock  while  reducing  its  cross-sectional  area.  With 
machine  steel  this  can  be  done  at  a  yellow  heat,  but  wrought 
iron  requires  a  welding  heat. 

When  the  stock  is  at  the  proper  heat,  this  drawing-out  can 
be  accomplished  by  hammering  it  over  the  large  part  of  the 
horn  with  a  hand  hammer,  as  shown  in  Fig.  24.  This  makes 
the  piece  increase  in  length  without  widening  it  very  much. 
If  it  were  hammered  on  the  face  of  the  anvil  a  large  amount 
of  energy  would  be  wasted,  due  to  the  sidewise  spreading  of 
the  stock. 


32 


DRAWING-OUT,  BENDING  AND  TWISTING 


In  drawing-out  stock  of  any  shape  it  should  first  be  ham- 
mered square  to  prevent  it  from  bursting.  This  also  makes 
the  grain  finer  and  improves  the  physical  properties  of  the 
material.  Even  when  a  round  bar  is  to  be  reduced  in  diameter 


Fig.  24.     DRAWING-OUT. 

it  should  be  first  hammered  square,  then  octagonal,  and  finally 
round. 

The  reason  for  this  procedure  can  be  explained  with  the 
aid  of  Fig.  25,  which  shows  the  cross-section  of  a  piece  of 
round  stock  that  is  being  slowly  revolved  while  hammering. 
The  blows  on  top  will  cause  the  stock  to  flatten  out  and  as- 
sume the  shape  indicated  by  the  dotted  line.  This  will  make 
the  sides,  A  and  A,  tend  to  pull  away  from  the  center.  As 


Fig.  25.  Fig.  26. 

the  piece  is  revolved  and  hammered  the  direction  of  this  pull 
will  change,  so  that  the  tendency  will  be  for  the  whole  outside 
surface  to  separate  from  the  center.  The  result  is  the  forma- 
tion of  cracks,  as  shown  in  Fig.  26.  These  make  the  iron 
structurally  weak. 

When  drawing  stock  down  to  a  conical  point,  as  in  Project 
3,  it  must  first  be  hammered  square  and  the  corners  then 
rounded  off.  If  this  is  not  done  the  point  will  split  or  burst. 

Squaring,   or   Truing-up,   Work. — When    drawing-out   a 


CUTTING  STOCK  33 

round  bar  to  a  square  one  there  is  danger  of  its  becoming  dia- 
mond-shaped in  cross-section,  as  shown  in  Fig.  27.  It  will,  in 
fact,  almost  invariably  assume  this  shape  if  the  bar  is  not 
heated  uniformly.  The  bar  may  be  trued-up  by  laying  it 
across  the  anvil  and  striking  it  as  indicated  by  the  arrow  so  as 
to  force  the  extra  metal  back  into  the  body  of  the  bar. 


I'ig.  27. 

Cutting  Cold  Stock. — In  cutting  cold  bars  of  soft  steel  or 
wrought  iron  with  a  cold  chisel  the  method  employed  should 
be  as  follows :  Around  the  bar  make  a  series  of  cuts  about 
one-fourth  of  the  way  thru,  taking  care  to  have  them  always 
at  right  angles  to  the  axis  of  the  bar.  Tilt  the  bar  slightly, 
and  place  the  partly  cut  section  at  the  outer  edge  of  the  anvil. 
By  hitting  the  projecting  end  a  sharp  blow  with  a  sledge  it 
should  break  off  easily. 

If  the  stock  becomes  slightly  warm  when  being  cut  in  this 
way,  cool  it  with  water;  otherwise  it  will  be  tough  and  will 
not  break  off. 

Cutting  Hot  Stock. — Hot  stock  must  be  cut  all  the  way 
thru,  since  it  is  generally  too  soft  to  be  very  easily  broken  off 
by  a  sledge  blow.  To  obtain  a  square  cut  at  one  end  of  a  bar 
the  hot  chisel  should  be  tilted  away  from  that  end  until  one 
side  of  the  cutting  edge  is  perpendicular  to  the  bar.  Hot 
stock  is  usually  cut  from  either  two  or  four  sides,  but  if  it  is 
flat  the  cutting  is  done  from  either  one  or  both  of  the  widei 


34  DRAWING-OUT,  BENDING  AND  TWISTING 

sides.  In  cutting  round  stock  the  bar  should  be  revolved 
toward  the  worker. 

The  cutting  edge  of  a  hot  chisel  will  become  soft  and  bend 
if  allowed  to  get  too  hot.  For  this  reason  it  is  necessary  to 
dip  it  in  water  frequently  to  cool  it  off.  It  should  also  be  re- 
moved from  the  cut  between  blows. 

In  using  a  chisel,  and  especially  a  hot  chisel,  never  allow 
its  cutting  edge  to  come  in  contact  with  the  hard  face  of  the 
anvil.  When  a  piece  has  been  nearly  cut  thru,  it  should  be 
moved  forward  until  the  cut  is  just  outside  the  edge  of  the 
anvil.  A  copper  plate  is  sometimes  used  for  protecting  the 
chisel  edge  when  cutting  thin  stock.  The  chisel  may  then  cut 
thru  the  stock  and  sink  into  the  copper  without  having  its 
edge  spoiled. 

A  hardie  is  used  in  much  the  same  manner  as  a  chisel. 
When  the  stock  has  been  nearly  cut  thru,  the  last  blow  or  two 
should  fall  on  the  far  side  of  the  hardie.  This  keeps  the  face 


Fig.  28. 

of  the  hammer  from  coming  in  contact  with  and  spoiling  the 
cutting  edge  of  the  hardie.  It  also  prevents  the  projecting  end 
from  flying  up  and  hitting  the  worker  in  the  face,  as  it  might 
if  this  were  not  done. 

Twisting. — When  twisting  stock,  it  should  first  be  marked 


PUNCHING 


35 


with  a  center-punch  at  the  points  where  the  twist  is  to  begin 
and  end.  The  section  to  be  twisted  is  heated  to  an  even  yellow 
heat.  The  piece  is  then  quickly  placed  in  a  vise  with  one  cen- 
ter-punch mark  in  line  with  one  edge  of  the  jaws,  as  shown  in 
Fig.  C,  Plate  V.  A  pair  of  flat-jawed  tongs  or  a  wrench  is 
used  to  grasp  the  piece  at  the  other  mark  in  the  same  manner. 
The  bar  can  then  be  twisted  as  much  as  required.  If  there  is 
no  vise  convenient,  two  pairs  of  tongs  may  be  used. 

In  order  to  obtain  a  uniform  twist  the  stock  must  be  uni- 
formly heated.  A,  B  and  C  of  Fig.  28  illustrate  the  effects 
produced  by  twisting  square,  octagonal,  and  flat  material  re- 
spectively. 


Fig.  29. 

Punching. — Two  kinds  of  punches  are  commonly  em- 
ployed for  punching  holes  in  hot  material.  The  straight  hand- 
punch  shown  at  A  in  Fig.  29  is  used  on  thin  stock,  while  the 
eye-punch  at  B  is  used  for  punching  holes  in  heavier  stock. 
These  punches  should  be  made  of  tool  steel,  since  they  bend 
too  easily  if  made  of  machine  steel. 

When  punching  thick  material,  the  hot  stock  is  laid  flat  on 
the  anvil  and  the  punch  driven  into  it  with  a  sledge  hammer. 
At  a  depth  of  about  %  mch  the  punch  is  removed  and  some 
green  or  dry  coal  placed  in  the  hole  to  prevent  sticking.  When 
the  punch  has  been  driven  three-fourths  of  the  way  thru,  as 
shown  as  C,  a  black  mark  will  appear  on  the  bottom  side. 


36  DRAWING-OUT,  BENDING  AND  TWISTING 

The  stock  is  then  reversed  and  the  punching  continued  from 
that  side,  as  at  D.  During  the  entire  operation  the  punch 
should  be  cooled  occasionally,  to  keep  it  from  softening  and 
bending.  Care  should  be  taken  when  finishing  the  punching 
to  have  the  punch  directly  above  the  hardie  or  the  pritchel 
hole,  in  order  to  allow  the  plug  to  drop  thru. 

A  clean-cut  hole  will  be  obtained  if  this  procedure  is  car- 
ried out;  but  if  the  punching  is  done  from  one  side  only,  a 
burr  will  be  raised  on  the  lower  side,  as  shown  at  E. 

Project  1.    Drawing-out  and  Bending  Ring.     (Plate  I.) 

This  project  is  given  for  the  purpose  of  familiarizing  the 
student  with  the  heating  of  machine  steel  or  wrought  iron  and 
the  use  of  the  hand-hammer. 

STEP  ONE. — The  round  stock  is  drawn  out  square,  as 
shown  at  1.  This  is  done  by  heating  about  3  or  4  inches  of  it 
at  one  end  to  a  yellow  heat,  and  reducing  it  with  a  hand- 
hammer  on  the  large  part  of  the  horn,  as  shown  in  Fig.  24. 

STEP  Two. — The  material  is  rounded  by  hammering  it  on 
the  corners,  making  it  first  octagonal  and  then  round.  It  is 
smoothed  up  either  by  placing  it  in  a  ^-inch  bottom-swage 
and  revolving  it  while  hammering  or  by  using  top-  and  bot- 
tom-swages. 

STEP  THREE. — A  piece  11^  inches  long  is  cut  off  of  the 
drawn-out  portion.  This  may  be  done  on  the  hardie  in  the 
manner  already  described.  Be  sure  to  have  the  last  blows  fall 
on  the  far  side  of  the  hardie,  to  avoid  spoiling  its  edge  and 
to  prevent  the  cut  portion  from  flying  up  into  the  face  ^:  the 
worker. 

STEP  FOUR. — About  a  third  of  the  stock  is  heated,  and  bent 
over  the  large  part  of  the  anvil,  as  shown  at  4.  The  hammer 
blows  should  fall  on  the  end  outside  of  the  horn,  and  not  on 
top  of  the  horn.  This  will  bend  the  material  without  marring 
it.  The  other  end  is  bent  in  the  same  manner. 


Project  1. 


Plate  I. 


DRAWING-OUT  flc  BENDING    RING 

Stock;      round  machine  steel 


© 


©  [ 


© 


-Hi- 


Method   of  Bending 


37 


38  DRAWING-OUT,  BENDING  AND  TWISTING 

STEP  FIVE. — The  piece  is  heated  and  held  with  a  pair  of 
link-tongs,  as  shown  in  Fig.  A.  The  bending  is  then  con- 
tinued by  hammering  as  indicated.  The  ring  is  finally  made 
circular  on  the  horn  of  the  anvil.  The  ends  must  be  cut  off 
with  a  hot  chisel  or  hardie  along  the  dotted  lines  shown. 

STEP  Six.- — The  ends  are  driven  together  and  the  round- 
ing finished.  When  the  ring  is  completed,  it  may  be  given  a 
black  finish  by  holding  it  over  a  smoky  fire  until  black  hot  and 
then  wiping  it  with  oily  waste. 

Project  2.     S-Hook.     (Plate  II.) 

STEP  ONE. — After  squaring  up  the  ends  of  the  stock,  heat 
about  half  of  the  piece  and  bend  one  end  over  the  horn.  Be 
sure  to  have  the  blows  fall  on  the  far  side  of  the  horn,  as  in 
the  previous  exercise. 

STEP  Two. — Continue  the  bending  until  the  piece  is  shaped 
as  shown. 

STEP  THREE. — Heat  the  other  end  and  bend  it  over  the 
horn  in  the  same  manner  as  before,  but  in  the  opposite  direc- 
tion. 

STEP  FOUR. — Complete  the  bending  by  making  the  hook 
appear  as  shown.  The  finished  hook  should  be  free  from 
rough  marks  caused  by  improper  bending. 


Project  2. 


Plate  II. 


S    HOOK 


Stock:  ^"x  82" round  Machine  Steel 
~]^ ' 4 


40  DRAWING-OUT,  BENDING  AND  TWISTING 

Projects.    Staples.    (Plate  III.) 

STEP  ONE. — Cut  the  stock  to  length,  then  hammer  out  the 
ends  to  a  square  or  a  chisel-point,  as  shown  at  la  and  Ib. 
Work  at  the  outer  edge  of  the  anvil,  to  avoid  hitting  the  anvil 
face  with  the  hand-hammer.  Both  anvil  and  hammer  facet 
may  be  chipped  or  broken  if  this  is  not  done. 

STEP  Two. — Heat  the  stock  at  the  center  and  bend  it  over 
the  horn,  taking  care  to  have  the  blows  fall  on  the  outside. 

STEP  THREE. — Finish  the  bending  operation,  and  cut  off 
the  ends  with  a  hardie.  If  the  ends  are  crooked  they  may  be 
straightened  on  the  hardie,  as  shown  in  Fig.  30. 


Fig.  30. 


Project  3. 


Plate  III. 


0) 


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I    §. 


/*^ 


i£-  i 

IT  1 


l! 


41 


42  DRAWING-OUT,  BENDING  AND  TWISTING 

Project  4.    Beam  Strap.    (Plate  IV.) 

STEP  ONE. — As  with  any  bent  shape,  the  length  of  stock 
required  for  this  project  is  determined  by  measuring  along 
the  center  line  of  the  finished  shape,  i.  e.,  along  the  dotted  line 
in  3.  The  location  of  the  right-angle  bend  and  the  beginning 
and  end  of  the  twist  should  be  marked  with  a  center-punch. 
This  is  done  on  the  edge  of  the  stock  before  it  is  heated.  A 
cold  chisel  should  not  be  used  for  marking,  since  the  cut  ex- 
pands and  starts  a  crack. 

STEP  Two. — Take  a  short  high  heat  at  the  center-punch 
mark  where  the  piece  is  to  be  bent,  and  lay  the  stock  on  the 
anvil  at  the  rounded  edge,  as  shown  in  Fig.  A.  The  center- 
punch  mark  should  not  come  quite  in  line  with  the  outer  edge 
of  the  anvil,  for  the  stock  has  a  tendency  to  move  forward 
during  the  bending  operation.  In  order  to  make  the  bend  as 
short  as  possible  the  bar  should  be  firmly  held  down  on  the 
anvil  with  a  sledge.  Strike  the  end  as  indicated,  and  bend  the 
stock  to  a  right  angle. 

STEP  THREE. — Square  up  the  corner  by  placing  the  project 
on  the  anvil,  as  in  Fig.  B,  and  striking  it  in  the  manner  indi- 
cated by  the  arrows.  It  should  also  be  reversed  on  the  anvil 
and  struck  on  the  end,  as  shown  in  Fig.  C.  By  striking  at  E 
the  stock  is  made  thicker  at  F,  forming  a  fillet  on  the  inside 
corner.  Care  should  be  taken  during  this  operation  to  keep 
the  angle  at  or  greater  than  90°  lest  the  stock  be  upset,  as 
in  Fig.  D,  forming  a  cold-shut  or  crack  on  the  inside  corner. 
This  would  make  the  angle  weak.  After  the  corner  has  been 
upset  and  hammered  to  shape,  it  is  smoothed  up  with  a  flatter. 

Caution. — Do  not  try  to  square  the  stock  by  placing  it  over 
a  corner  of  the  anvil,  as  it  will  then  be  hammered  too  thin. 

STEP  FOUR. — Take  a  uniform  yellow  heat  on  the  stock,  and 
place  one  end  in  a  vise.  Give  it  a  quarter-turn  with  a  pair  of 
flat-jawed  tongs  in  the  manner  already  described. 


Project  4. 


Plate  IV. 


BEAM   STRAP 

Stock  ••  |  x  1  j  x!2    wrot  iron  or  machine  steel 


—3" 4—- -2s" ^ 2f— -^ 3f—       -- 1 


43 


Projects.    Twisted  Gate-Hook.    (Plate  V.) 

STEP  ONE.— Cut  a  piece  of  &-inch  square  machine  steel  to 
the  size  indicated,  and  mark  it  with  a  center-punch,  as  shown 
at  1. 

STEP  Two. — To  form  a  shoulder,  heat  one  end  of  the  stock 
and  place  it  with  the  center-punch  mark  directly  above  the 
inner  edge  of  the  anvil.  Rest  the  set-hammer  on  top  of  the 
piece  so  that  its  side  edge  is  in  line  with  the  edge  of  the 
anvil,  as  in  Fig.  A.  The  stock  should  then  be  turned  while 
the  set-hammer  is  being  hit,  or  the  shoulder  will  be  worked 
in  faster  on  one  side  than  on  another.  Care  should  be  taken  to 
keep  the  shoulder  exactly  even  with  the  edge  of  the  anvil. 

STEP  THREE. — When  the  shoulder  has  been  formed,  as 
shown  at  the  end,  D,  in  2,  the  end  is  hammered  out  square  and 
then  round.  It  is  finished  between  top-and  bottom-swages. 
The  other  end  of  the  piece  is  shouldered  and  drawn  out  in  the 
same  manner.  If  the  shoulder  is  not  square,  it  may  be  trued 
up  by  inserting  the  swaged  end  in  a  heading-tool,  as  shown  in 
Fig.  B,  and  striking  on  the  opposite  end  of  the  stock. 

The  end,  D,  is  then  pointed  by  hammering  it  to  a  square 
point,  rounding  off  the  corners,  and  cutting  it  to  length. 

STEP  FOUR. — To  bend  the  eye,  the  stock  is  heated  uni- 
formly and  the  bend  started  over  the  rounded  edge  of  the 
anvil.  The  square  stock  at  the  shoulder  should  be  cooled,  to 
prevent  its  bending.  The  eye  is  finished  on  the  horn  of  the 
anvil  in  the  same  manner  as  the  S-hook. 

The  hook  is  bent  in  much  the  same  way.  About  YZ  inch 
of  the  point  should  be  cooled  and  the  blows  allowed  to  fall 
on  this  cold  part,  in  order  to  avoid  marring  the  stock. 

STEP  FIVE. — Before  twisting  the  middle  section,  center-- 
punch marks  should  be  made  \y2  inches  from  each  shoulder, 
leaving  \y2  inches  between  these  marks.  This  portion  is 
heated  to  an  even  yellow  and  placed  in  a  vise,  as  shown  in 
Fig.  C.  With  the  aid  of  a  pair  of  flat- jawed  tongs  the  stock 
is  given  one  complete  turn. 

The  hook  should  be  filed  while  hot,  to  remove  the  scale, 
and  then  blackened. 

44 


Project  5. 


Plate  V. 


GATE    HOOK 


Stock:  7|  x  f|"x  ^"Machine  Steel 

©  ~^~      7>aT         ~~    ~ 

k-ir-H-^v-  ~4i^ 


Center    punch   marks 


©    t=f^ 


© 


One    complete     turn  J 


45 


CHAPTER  III. 
COMMON  WELDS. 

The  Lap  Weld  is  the  one  ordinarily  used  for  joining  flat, 
square,  or  round  bars.  In  order  that  the  cross-section  of  the 
material  at  the  weld  be  the  same  as  that  of  the  stock,  it  is 
generally  necessary  to  upset  the  ends  before  welding. 

Upsetting. — When  the  length  of  a  piece  of  stock  is  de- 
creased and  its  cross-sectional  area  increased  at  any  point,  it 
is  said  to  be  upset  at  that  point.  Before  this  can  be  done  to 
the  end  of  a  piece  of  wrought  iron,  it  is  necessary  to  bring  it 
to  a  welding  heat.  A  section  in  the  middle  of  the  stock  does 
not  have  to  be  heated  so  much.  If  the  upsetting  is  to  be  at 
one  end,  the  stock  should  first  be  hammered  on  all  sides,  to 
prevent  it  from  bursting  thru  the  slag  seams  at  the  end.  When 
the  end  of  a  short  piece  is  to  be  upset,  it  may  be  done  by 
holding  the  piece  vertically  with  a  pair  of  link-tongs,  the  hot 
end  resting  on  the  face  of  the  anvil,  and  striking  the  top  end 
with  a  hand-hammer.  Heavy  blows  are  necessary,  and  as  they 
have  a  tendency  to  bend  the  stock  it  must  be  straightened  oc- 
casionally. The  end  of  a  long  piece  may  be  upset  by  gripping 
the  cold  end  with  the  hands  and  striking  the  hot  one  against 
the  face  of  the  anvil. 

The  object  of  upsetting  a  piece  before  welding  is  to  make 
allowance  for  the  iron  which  is  lost  thru  scaling  and  burning, 
and  for  the  drawing-out  caused  by  the  hammering  required 
for  a  sound  weld.  If  the  stock  is  hammered  out  too  thin  at 
the  weld,  it  may  be  upset  again  at  that  point,  but  this  is  a 
more  difficult  operation  than  upsetting  before  welding.  It  is 
therefore  better  to  upset  the  ends  of  the  original  bar  too  much 
than  not  enough,  as  the  surplus  stock  can  very  quickly  be 
hammered  out.  The  amount  of  upsetting  required  depends 
entirely  upon  the  number  of  heats  taken  in  welding.  Every 

46 


USE  OF  FLUX  47 

time  a  bar  of  iron  is  brought  to  the  welding  heat  there  is  a 
portion  of  the  outside  surface  wasted  on  account  of  scaling 
and  burning.  The  amount  of  material  allowed  for  waste  in 
welding  therefore  depends  upon  the  number  of  heats  required 
to  make  a  sound  weld.  This  allowance  is  generally  from  one- 
fourth  to  three-fourths  of  the  diameter  of  the  stock. 

Scarfing  is  the  process  of  shaping  the  ends  of  stock 
so  that  when  they  are  welded  together  a  smooth  joint  will  be 
obtained.  The  shapes  of  these  scarfs  depend  to  a  large  extent 
upon  the  character  of  the  weld,  and  will  be  taken  up  in  detail 
in  Projects  6  to  17.  In  general  the  parts  of  the  scarfs  which 
are  placed  in  contact  in  welding  should  be  convex,  as  shown 
at  3  in  Plate  VII.  The  two  centers  will  then  touch  first,  and 
the  molten  oxide  will  be  allowed  to  escape.  If  the  scarfs  were 
made  concave  this  oxide  could  not  escape  or  be  squeezed  out, 
and  the  weld  would  be  a  poor  and  unsound  one. 

Use  of  Fluxes  in  Welding. — When  heating  a  piece  of 
common  iron  or  steel  for  welding,  oxidation  takes  place  and 
a  thin  film  of  oxide  of  iron  is  formed  on  the  surface.  This 
oxide,  or  scale,  must  be  heated  to  a  high  temperature  before 
becoming  fluid  enough  to  run  off  and  permit  a  sound  weld. 

Wrought  iron  may  be  heated  enough  to  melt  off  this  oxide 
without  being  burned,  but  steel  would  be  injured  if  brought 
to  such  a  high  temperature.  It  is  therefore  necessary,  when 
welding  both  high-  and  low-carbon  steel,  to  use  a  flux,  such 
as  powdered  borax,  in  order  to  lower  the  melting  point  of  the 
oxide.  A  flux  is  also  often  used  when  welding  wrought  iron, 
but  is  not  essential.  Fluxes  do  not  act  as  cements,  but  merely 
make  the  iron  weldable  at  a  lower  temperature. 

Method  of  Using  Flux. — After  the  pieces  in  the  fire  have 
reached  a  yellow  heat,  some  flux  is  thrown  or  sprinkled  on  the 
scarfs,  or  parts  to  be  welded,  and  the  heating  continued  up  to 
the  welding  heat.  As  the  flux  melts  it  flows  over  the  scarf, 
forming  a  coat  or  covering.  This  dissolves  the  oxide  already 
formed  and  prevents  further  oxidation. 


48  COMMON    WELDS 

The  flux  used  when  welding  wrought  iron  is  generally 
clean,  sharp  sand.  There  are  various  welding  compounds  on 
the  market,  some  of  which  contain  borax  and  iron  filings. 
Most  of  them  contain  borax,  and  are  used  mainly  when  weld- 
ing steel. 

Project  6.    Practice  Welds— Fagot.     (Plate  VI.) 

The  Fagot  Weld  is  given  as  a  project  in  order  that  the 
student  may  (1)  become  familiar  with  welding  heats,  (2) 
learn  to  use  the  hand-hammer  effectively,  (3)  have  further 
practice  in  the  drawing-out  of  wrought  iron,  (4)  and  also  for 
economy,  since  old  links,  rings,  or  pieces  of  scrap  iron  may  be 
used  to  good  advantage. 

This  weld  may  be  made  by  placing  two  or  more  pieces  of 
iron  on  top  of  each  other  and  welding  them  for  the  entire 
length.  Another  method  is  to  bend  the  end  of  a  piece  of  stock 
once  or  twice,  as  in  la  and  2a,  and  weld  it  into  a  solid  lump. 

If  a  link  or  ring  is  available,  it  can  be  heated  and  closed 
for  half  its  length,  as  in  3a.  This  portion  is  then  welded  and 
hammered  out  square.  When  the  other  end  has  been  treated 
in  the  same  manner,  the  entire  piece  is  hammered  octagonal, 
then  round,  and  finally  smoothed  up  between  top-  and  bottom- 
swages.  This  finished  piece  may  be  used  again  for  making  a 
ring  or  link. 

Project  7.    Round  Lap  Weld.     (Plate  VII.) 

STEP  ONE. — Upset  one  end  of  each  of  two  pieces  of  round 
stock  for  about  2  inches,  as  shown  at  1.  This  is  done  by  heat- 
ing the  ends  to  a  welding  heat  and  hitting  them  against  the 
face  of  the  anvil,  in  the  manner  already  described. 

STEP  Two. — The  scarf  is  started  by  placing  the  stock  on 
the  face  of  the  anvil,  with  the  upset  portion  near  the  rounded 
edge,  and  hitting  it  with  the  face  of  a  hand-hammer.  After 


Project  6. 


Plate  VI. 


PRACTICE    WELDS  -  FAGOT. 


©   G 

[•»*•• 


Stock  I  xlV  Wrot  Iron 


Srock  |"xlV'Wrot  Iron 


To  be  made  from  link  or  ring 

Finished  sizes  will  depend  upon  stock  used 


c 


Half    to  be  welded   at  a  time. 


After  welding  whole   piece,  hammer  square, 
octagonal,  then  round   as  shown  below. 


49 


50  COMMON    WELDS 

a  few  blows  the  peen  is  used,  as  shown  in  Fig.  A.  These 
blows  should  come  at  an  angle  of  about  45°,  in  order  to  force 
the  material  back  and  form  a  thick  ridge  at  the  heel  of  the 
scarf,  as  shown  at  2.  The  scarf  at  this  point  should  be  slightly 
tapered. 

STEP  THREE. — The  scarf  is  finished  at  the  rounded  edge  of 
the  anvil  with  the  face  of  the  hammer.  This  is  done  to  avoid 
hitting  the  hammer  against  the  sharp  edge  of  the  anvil.  The 
length  of  the  scarf  should  be  about  one  and  one-half  times 
the  thickness  of  the  bar  at  the  upset  portion. 

The  scarf  is  worked  down  to  a  point,  as  shown  at  3,  in 
order  to  facilitate  welding  the  end  of  the  scarf.  If  these  ends 
were  very  wide  several  blows  would  be  necessary  to  weld 
them,  and,  since  they  cool  very  rapidly,  considerable  skill  and 
speed  would  be  required. 

STEP  FOUR. — When  heating  the  stock  for  welding  have  a 
good  bed  of  hot  coals.  Place  the  short  piece  at  the  right  of 
the  long  one,  the  scarfs  of  both  being  face  down,  and  cover 
them  with  coke.  Heat  slowly,  to  insure  a  uniform  tempera- 
ture thruout  the  scarfed  portions.  If  one  piece  should  heat 
faster  than  the  other,  pull  it  back  a  little  from  the  center  of 
the  fire.  Both  pieces  must  be  at  a  welding  heat  at  the  same 
time. 

When  at  the  welding  heat  remove  the  pieces  from  the  fire, 
taking  the  short  piece  in  the  right  hand  and  the  long  one  in 
the  left.  Keeping  the  scarf  side  down,  give  them  each  a  quick 
blow  on  the  horn  of  the  anvil,  to  dislodge  any  dirt  on  the 
faces  of  the  scarfs.  Place  the  short  piece  on  the  anvil  with 
the  scarf  up,  as  shown  in  Fig.  C.  This  piece  is  not  so  liable 
to  overbalance  and  fall  to  the  floor,  as  sometimes  happens 
when  welding  without  assistance,  if  the  end  of  the  scarf  comes 
nearly  to  the  inner  edge  of  the  anvil.  Steady  the  scarfed  end 
of  the  other  piece  against  the  edge  of  the  anvil,  as  shown  in 
Fig.  C,  and  bring  it  to  the  desired  position  above  the  short 


Project  7. 


Plate  VII. 


ROUND  LAP  WELD 

Stock:  |"  Round    Machine    Steel  or    Wrot  Iron . 
1  piece    about  16"  and  1   piece  about  10"  long 


® 


iO 


^ 


R9  A 

Method  of  starting   scarf 


Method  of  finishing  scarf 


^ 


Fig.D      Appearance  of  weld  after 

first  blow 


® 


51 


52  COMMON    WELDS 

piece.  The  end  of  one  scarf  should  lap  over  the  thick  ridge, 
or  heel,  of  the  other,  as  in  Fig.  D. 

With  a  hand-hammer  deliver  a  few  sharp  blows,  to  stick 
the  body  of  the  material.  The  ends  of  the  scarfs  should  then 
be  hammered  down,  otherwise  they  will  become  too  cold  and 
will  not  stick.  If  the  scarfs  are  not  thoroly  welded  at  the 
first  heat,  put  the  piece  back  into  the  fire  and  take  another 
welding  heat  on  it. 

STEP  FIVE. — After  the  weld  has  been  made,  the  scale 
should  be  cleaned  off  with  a  file,  since  it  pits  the  material.  The 
bar  is  then  finished  between  top-  and  bottom-swages. 

Projects.    Flat  Lap  Weld.    (Plate  VIII.) 

STEP  ONE. — The  stock  is  upset  for  about  2  inches  in  the 
manner  previously  described. 

STEP  Two. — The  scarf  is  started  in  the  same  way  as  for 
the  round  lap  weld.  It  should  not,  however,  taper  very  much 
at  the  end. 

STEP  THREE. — The  finished  scarf  should  be  made  the  same 
width  as  the  bar  at  the  thick  ridge,  and  slightly  tapered  to- 
ward the  end,  as  at  3. 

STEP  FOUR. — The  two  pieces  are  welded  together  in  much 
the  same  manner  as  the  round  stock  of  Project  7.  It  is  ad- 
visable, tho,  to  use  a  heavy  hand-hammer  in  welding  flat  oars. 

STEP  FIVE. — When  the  welding  is  finished,  the  scale  should 
be  cleaned  off  with  a  file  and  the  piece  smoothed  up  with  a 
flatter. 


Project  8. 


Plate  VIIL 


FL 

© 
© 

® 
® 

© 

AT   LAP    WELD 
Stock:  |xl^"yl8"Wrot  Iron 

i)                                               %                                                                f 

il                jt                      ? 

I 

il                                                                        [* 

II 

il                                                                              '1 

Taper  edges  slightly  y^ 

11                           } 

-I'- 

ll                                                                                                     \ 

(1                                          -_^~~                       1 

Po?iTioi  of  pieces  on  anvil    S           ... 
for  welding  .      Inner  edge 

—  vk- 

1       \ 

53 


54  COMMON    WELDS 

Project  9.     Links  of  Chain.    (Plate  IX.) 

The  length  of  the  material  required  for  a  link  is  found  by 
measuring  the  distance  around  at  the  center  of  the  stock.  To 
compute  this  distance  the  desired  link,  shown  at  4,  should  be 
separated  into  two  semi-circular  ends  and  two  straight  con- 
necting sections.  The  mean  diameter  of  the  ends  is  \l/\ 
inches;  so  1^4  X  31/?,  or  3|f  inches,  is  required  for  them. 
The  connecting  sections  are  each  1^  inches  long.  The  total 
length  is  then  3{f  +  2  X  1%  =  &\\  inches.  To  this  should 
be  added  a  small  amount,  about  y&  inch,  for  the  waste  in 
welding. 

STEP  ONE. — Square  up  the  ends  of  the  material,  and  heat 
the  middle  uniformly  for  about  3  inches.  Bend  it  halfway  on 
the  horn,  taking  care  to  have  the  blows  fall  on  the  cold  pro- 
jecting end.  It  should  then  be  reversed  and  the  other  end  bent 
over  in  the  same  manner,  forming  a  U,  as  shown  at  1.  The 
reason  for  this  reversal  is  that  if  the  U  were  formed  by  hitting 
on  one  end  only  that  side  of  the  U  would  be  the  shorter  of 
the  two.  If  one  side  should  be  longer  than  the  other,  it  may 
be  shortened  by  heating  the  semi-circular  portion,  placing  it 
on  a  bottom-swage,  the  shorter  leg  being  held  vertical  with  a 
pair  of  link-tongs,  and  striking  on  the  end  of  the  longer  leg. 

STEP  Two. — The  ends  are  brought  to  a  yellow  heat  and 
scarfed  by  placing  one  end  on  the  anvil,  as  shown  at  A,  and 
striking  a  number  of  blows,  moving  the  U  toward  the  horn 
after  each  one.  This  leaves  a  series  of  notches  on  the  under 
side  of  the  piece,  as  shown  at  2.  The  U  is  then  turned  over, 
and  the  other  end  treated  in  the  same  manner.  The  scarfs 
are  finished  on  the  face  of  the  anvil  with  the  peen  or  the  heel 
of  a  hand-hammer.  They  should  not  be  less  than  -^  inch 
thick  at  the  end,  or  they  will  cool  too  quickly  and  it  will  be 
almost  impossible  to  weld  them. 

STEP  THREE. — Bring  the  ends  together,  as  at  3,  taking  care 
to  have  the  end  of  the  top  scarf  pointed  toward  the  right.  If 


Project  9. 


Plate  IX. 


LINK5   OF   CHAIN  „       „ 

Stock :  6  pieces  fx6:4    Wrot  iron 


©  © 


© 

T 

I 


Fig.  A 
Method  of  Scarfing 


55 


56 


COMMON   WELDS 


it  points  to  the  left,  the  scarf  is  left-hand  and  is  harder  to 
weld.  The  link  should  be  shaped  so  that  the  end  to  be  welded 
is  narrower  than  the  other.  The  stock  is  then  less  liable  to 
be  hammered  small  on  either  side  of  the  weld,  and  the  semi- 
circular end  will  be  about  the  right  size  when  the  weld  is 
finished. 

STEP  FOUR. — Take  a  welding  heat  and  weld  the  joint  with 
a  few  quick  blows  of  the  hand-hammer.  The  link  is  finished 
on  the  horn  of  the  anvil. 

STEP  FIVE. — When  joining  links,  the  connecting  one  is 
scarfed  and  its  ends  brought  together  ready  for  welding.  The 


Fig  31. 

end,  A,  of  the  link  is  then  heated,  the  scarfs  spread  apart,  as 
shown  in  Fig.  31,  the  links  slipped  on,  and  the  scarfs  brought 
together  again.  This  connecting  link  is  welded  in  the  same 
manner  as  the  others. 

Welded  Ring. — A  ring  formed  from  round  stock  may  be 
made  in  two  ways,  i.  e.,  by  scarfing  before  or  after  bending  it 
into  shape.  The  second  of  these  is  the  less  difficult,  as  the 
scarfs  are  then  more  easily  fitted  and  the  stock  on  either  side 
of  the  weld  is  not  likely  to  become  thin. 

The  amount  of  material  required  to  make  it  is  computed 
from  its  mean  diameter.  For  the  following  two  projects  this 


WELDED  RING  57 

mean  diameter  is  3%  inches,  as  shown  in  Plate  X.  The  mean 
circumference  of  the  ring  is  then  3^4  X  3#,  or  approximately 
lQl/4  inches.  To  this  must  be  added  an  allowance  for  waste 
in  welding,  depending  on  the  number  of  heats  necessary.  For 
a  student  this  would  be  about  %  or  ^  inch,  so  the  total  length 
of  stock  required  is  10^4  inches. 


58  COMMON    WELDS 

Project  10.    Ring— Round  Lap  Weld.    (Plate  X.) 

STEP  ONE. — Upset  the  ends  of  the  stock  until  its  length  is 
9}i  inches. 

STEP  Two. — Scarf  the  ends  as  shown  at  2  in  the  same 
manner  as  for  a  simple  lap  weld  for  round  stock. 

STEP  THREE. — Heat  one-third  of  the  stock  and  bend  it  over 
the  large  part  of  the  horn,  keeping  the  straight  side  of  the 
scarfed  end  toward  the  right.  Srtike  on  the  projecting  end, 
as  shown,  in  order  not  to  mar  the  material.  The  other  end  is 
bent  in  the  same  manner,  making  the  project  appear  as  shown 
at  3. 

STEP  FOUR. — Heat  the  center  section  and  complete  the 
bending  by  holding  the  piece  upright  on  the  anvil  with  a  pair 
of  link-tongs  and  knocking  the  scarfs  together.  The  point  of 
the  top  scarf  should  look  toward  the  right,  as  at  4.  If  the 
scarfs  do  not  meet  squarely,  shape  the  ring  on  the  horn. 
Hammer  the  scarfs  together  on  the  face  of  the  anvil,  so  that 
no  dirt  can  get  in  between  them. 

STEP  FIVE. — Heat  and  weld  the  ring  in  the  same  manner  as 
a  link.  When  the  welding  is  finished,  smooth  the  ring  on  the 
horn  of  the  anvil  with  a  top-swage.  To  make  the  ring  cir- 
cular, heat  it  all  over  and  drive  it  down  on  the  cone  with  a 
hand-hammer. 


Project   10. 


Plate  X. 


RING 


© 


o 


(D 


LAP- WELD  SCARF 

Stock.  i"xlO$"  Wror  iron 


-10  J- 


-  Upset  TO  9f  - 


59 


60  COMMON    WELDS 

Project  11.     Ring— Link  Scarf.     (Plate  XL) 

STEP  ONE. — Upset  the  ends  of  the  stock  until  its  length  is 
9^4  inches. 

STEP  Two. — Bend  the  ends  to  the  form  shown  at  2  in  the 
same  manner  as  in  the  previous  project. 

STEP  THREE. — Heat  the  middle  section  and  bend  the  ends 
to  within  a  short  distance  of  each  other,  as  at  3. 

STEP  FOUR. — Scarf  the  ends  in  the  same  way  as  for  a  link. 

STEP  FIVE. — Bring  the  scarfed  ends  together,  as  at  5. 

STEP  Six. — Weld  the  two  ends  and  finish  the  ring  in  the 
same  manner  as  in  the  previous  project. 

Project  12.     Forged  Hook.     (Plates  XII  and  XIII.) 

Forged  hooks  are  made  from  tool  steel,  Norway  iron,  or 
machine  steel.  The  one  in  this  project  is  to  be  made  from 
24  -inch  round  machine  steel. 

STEP  ONE. — Cut  the  stock  6  inches  long.  Heat  about  ll/2 
inches  at  one  end  to  a  yellow  heat  and  upset  it  as  at  1,  de- 
creasing its  length  to  5y2  inches.  A  longer  piece  may  be  used 
more  advantageously,  since  the  end  can  then  be  upset  and  the 
eye  finished  without  the  use  of  tongs.  If  a  long  piece  is  used, 
care  should  be  taken  to  mark  it  6  inches  from  the  end  with  a 
center-punch  before  upsetting. 

STEP  Two. — Flatten  the  upset  end  until  it  is  ^2  inch  thick, 
as  at  2. 

STEP  THREE. — Use  ^-inch  top-  and  bottom-fullers  or  a 
necking-tool  to  fuller  the  neck  to  the  form  shown  at  3. 

STEP  FOUR. — Round  the  end  or  head  by  placing  one  cor- 
ner of  it  on  the  face  of  the  anvil  and  using  the  necking-tool 
on  the  shoulder,  as  in  Fig.  32.  Treat  the  other  corner  in  the 
same  manner.  Rounding  may  be  finished  with  the  hand- 
hammer  by  holding  the  piece  over  the  rounded  edge  of  the 
anvil  and  striking  it  as  shown  in  Fig.  33.  This  end  should  be 


Project  11. 


Plate  XI. 


RING 


LINK  SCARF 
Stock;  ?x  10f   round  wror  iron 


61 


62 


COMMON    WELDS 


forged  as  nearly  round  as  practicable  before  the  hole  is 
punched  in  it. 

STEP  FIVE. — Punch  a  ^-inch  hole  in  the  forged  end  or 
head,  as  at  5,  and  draw  the  neck  out  square  with  the  hand- 
hammer.  While  doing  this  allow  the  eye  to  extend  over  the 
rounded  edge  of  the  anvil,  in  order  to  prevent  the  filleted  cor- 
ners from  becoming  sharp. 

STEP  Six. — Round  the  inside  edges  of  the  hole  over  the 
horn,  as  shown  in  Fig.  34,  and  finish  or  smooth  the  outside 


Fig.  3; 


Fig.  33. 


Fig.  34. 


with  a  ^2-inch  top-swage.  Make  the  hole  circular  by  driving 
a  tapered  pin  thru  it.  The  finished  eye  should  then  appear 
as  if  made  from  round  stock. 

The  neck  is  hammered  round  and  finished  with  %-inck 
tapered  top-  and  bottom-swages.  If,  when  this  is  done,  the 
stock  is  too  long,  it  should  be  cut  to  the  length  given  at  6. 

STEP  SEVEN. — Draw  down  the  end  to  a  square  point,  work- 
ing at  the  rounded  edge  of  the  anvil  and  holding  the  stock  at 
such  an  angle  with  the  anvil  face  as  will  bring  the  point  in 
the  center  line. 

STEP  EIGHT. — Round  off  the  corners  of  the  point,  as  at  8. 
The  length  of  a  hook  from  the  neck,  or  shoulder,  of  the  eye 
to  the  extreme  end  should  be  eight  times  the  diameter  of  its 


Project   12. 


Plate  XII. 


FORGED  HOOK 

Stock  ijx 6  round  machine  steel 


© 


-54- 


1. 


® 


'7  Hr 


top  Q  bottom  fuller  or  necking  topi 

iplF 


C 


Drawn  down  square 


63 


Project  12. 


Plate  XIII 


FORGED  HOOK-GONT. 


I rfr-ie: 


Dimensions  onffnishad 
^ok  are  approxfmdte 


LlneAB  thru  eye  should  also  pass  thru  canter  of  hook 


64 


COMMON   EYE-BOLT  65 

largest  cross-section.  This  length  is  6  inches  for  the  hook 
given. 

STEP  NINE. — Bend  the  point  over  the  horn,  as  shown  at  9. 

STEP  TEN. — In  bending  the  hook,  heat  it  for  about  4  inches 
at  the  center,  and  cool  the  neck  and  point.  Place  it  on  the 
large  part  of  the  horn,  with  the  cold  tip  projecting  over.  A 
sledge  should  be  held  on  top  of  it,  in  order  to  prevent  it  from 
slipping  over  the  horn  too  far  when  hit.  Strike  the  project- 
ing tip  with  a  hand-hammer,  moving  the  hook  toward  the 
point  of  the  horn  as  the  bending  progresses.  It  should  be 
bent  to  the  form  shown  at  10.  If  it  is  necessary  to  change  the 
shape  of  the  hook  on  the  horn,  a  top-swage  should  be  used. 
This  leaves  the  hook  free  from  marks  of  the  hand-hammer. 

STEP  ELEVEN. — Take  a  short  heat  at  the  neck  and  bend 
the  eye  back  over  the  horn.  The  finished  hook,  shown  at  11, 
should  be  heated  and  the  scale  removed  with  a  file.  It  may 
then  be  attached  with  a  link  to  the  chain  of  Project  9. 

Project  13.     Common  Eye-Bolt.  (Plate  XIV.) 

STEP  ONE. — Cut  a  piece  of  J^-inch  round  wrought  iron 
\2l/4  inches  long.  Heat  one  end  to  a  welding  heat  and  scarf 
it,  as  shown  at  1. 

STEP  Two. — Bend  the  scarf  over  the  rounded  edge  of  the 
anvil  and  mark  it  with  a  center-punch,  as  shown  at  2. 

STEP  THREE. — Heat  about  7  inches  of  the  stock  at  the 
scarfed  end  to  a  uniform  yellow  heat.  The  bend  is  then 
started  by  placing  the  stock  with  the  center-punch  mark  above 
the  rounded  edge  of  the  anvil,  and  striking  on  the  projecting 
end  with  the  peen  of  a  hand-hammer. 

STEP  FOUR— Finish  the  bending  on  the  horn,  striking  on 
the  scarf,  to  avoid  marring  the  stock. 

STEP  FIVE. — Place  a  drift-pin,  or  a  piece  of  round  stock 


Project  13. 


Plate  XIV. 


COMMON    EYE.  BOLT 


Stock:  £"  Round  WroT  Iron 


d 


© 


® 


Start  outside    of  bend    opposite 
center   punch  marks 


66 


COMMON   HINGE  67 

slightly  larger  than  the  finished  hole,  in  the  eye  and  bring  the 
scarf  and  shank  together,  as  at  5. 

STEP  Six. — Heat  the  stock  slowly  to  a  welding  heat,  and 
weld  down  the  scarfed  end.  A  necking-tool  or  a  top-fuller  is 
used  in  rounding  the  shoulder.  The  welding  should  be  finished 
with  a  hand-hammer  at  the  rounded  edge  of  the  anvil.  Smooth 
up  the  stock  at  the  weld  with  a  top-  and  a  bottom-swage, 
and  drive  a  drift-pin  into  the  hole  to  make  it  symmetrical. 
While  still  hot  the  scale  should  be  removed  with  a  file. 


Fig.  35. 

One  of  the  commonest  applications  of  this  project  is  the 
clevis  shown  in  Fig.  35.  This  is  formed  by  making  an  eye  at 
each  end  of  a  piece  of  stock,  and  bending  it  into  the  form  of 
a  U. 

Project  14.  Common  Hinge.   (Plate  XV.) 

STEP  ONE. — Scarf  the  end  of  a  piece  of  wrought  iron 
l/4  X  1/4  inch  X  U  inches,  as  shown  at  1,  and  make  a  center- 
punch  mark  on  one  edge  4^4  inches  from  the  end. 

STEP  Two. — Heat  about  5  inches  of  the  piece  at  the  scarfed 
end,  and  place  it  on  the  anvil  with  the  scarfed  side  down. 
The  center-punch  mark  should  come  almost  in  line  with  the 
outer  rounded  edge  of  the  anvil.  Bend  as  at  2. 

STEP  THREE. — Continue  the  bending  on  the  horn,  and  close 
the  eye  on  a  pin  which  is  slightly  larger  than  the  finished  hole. 


Project  14. 


Plate  XV. 


COMMON  HINGE: 


Stock:  i"x  U'x  11"  WroT  iron 


Width  of  end  of  scarf  should  be  slightly  less  than  width  of  stock 


© 


cue 


-Center    punch  mark-, 


3     C 


0 


68 


FLAT  RING  69 

STEP  FOUR. — In  placing  the  piece  in  the  fire  have  the  scarf 
down,  in  order  to  avoid  burning  the  eye.  When  the  piece  is  at 
the  welding  heat,  it  should  be  removed  from  the  fire  and  laid 
on  the  anvil  with  the  scarf  up  and  the  eye  against  the  rounded 
edge  of  the  anvil.  If  this  were  not  done  and  it  were  welded 
over  the  sharp  edge  of  the  anvil,  the  neck  would  have  a  sharp 
corner  instead  of  being  rounded,  as  shown  at  4.  The  weld- 
ing is  done  with  a  heavy  hand-hammer. 

After  the  welding  has  been  completed,  a  pin  should  be  driven 
into  the  hole  and  a  top-swage  used  to  smooth  the  eye.  A 
flatter  may  be  used  to  smooth  the  stock  at  the  weld. 

Project  15.     Flat  Ring.     (Plate  XVI.) 

STEP  ONE. — Cut  a  piece  of  l/^  X  1%-inch  wrought  iron  14 
inches  long,  as  shown,  and  heat  one  end  for  about  2^2  inches. 
Upset  it  at  an  angle,  as  shown  at  1.  If,  while  doing  this,  most 
of  the  upsetting  occurs  at  the  tip,  the  extreme  end  should  be 
cooled  off.  To  decrease  the  width  at  the  upset  portion  it  should 
be  hammered  on  the  longer  edge  at  A.  This  will  keep  both 
edges  the  same  in  thickness.  Upset  the  other  end  in  the  same 
manner. 

STEP  Two. — Scarf  the  ends  as  shown  at  2,  taking  care  to 
have  the  scarfs  on.  opposite  sides  of  the  stock. 

STEP  THREE. — Heat  one  end  of  the  stock  for  about  4 
inches,  cool  the  corner,  B,  and  bend  the  end  over  the  horn. 
The  hammer  blows  should  fall  on  B.  Bend  the  other  end  in 
the  same  manner. 

STEP  FOUR. — Heat  the  center  of  the  stock,  and  finish  the 
bending  in  the  same  manner  as  for  the  ring  in  Project  1. 
The  scarfs  should  come  squarely  together  and  be  closed 
tightly,  as  at  4,  to  prevent  dirt  from  getting  in  between  them. 

STEP  FIVE. — Bring  the  scarfs  slowly  to  the  welding  heat, 
and  weld  them  together  on  the  face  of  the  anvil  with  a  heavy 


Project  15. 


Plate  XVI. 


FLAT  RING 


Stock:  3x15x14"  Wrot  Iron 


I  JfL 


II 


UpseT  to   I2l" 


© 


on 


_ I?2" 


® 


® 


70 


BAND   RING  71 

hand-hammer.  Finish  the  edges  on  the  horn,  then  smooth  the 
sides  with  a  flatter.  The  ring  should  be  made  circular  on  a 
cone,  and  the  scale  removed  with  a  file. 

Project  16.     Band  Ring.     (Plate  XVII.) 

STEP  ONE. — Cut  the  stock  to  length,  and  upset  each  end 
for  about  2  inches. 

STEP  Two. — Scarf  the  ends  the  same  as  for  a  flat  weld, 
taking  care  to  have  the  scarfs  come  on  opposite  sides  of  the 
stock,  as  shown  at  2. 

STEP  THREE. — Heat  the  piece,  and  bend  it  into  shape  in  the 
same  manner  as  the  ring  of  Project  1. 

STEP  FOUR. — Bring  the  scarfs  tightly  together,  as  at  4. 

STEP  FIVE. — Heat  the  scarfs  slowly,  to  prevent  the  outer 
one  from  burning  before  the  inner  one  is  hot  enough  to  weld. 
Weld  the  ring  over  the  horn  of  the  anvil,  and  finish  it  with  a 
flatter.  It  should  then  be  heated  uniformly  thruout,  and 
rounded  on  a  cone.  In  order  to  prevent  it  from  becoming 
tapered  while  doing  this,  it  must  be  reversed  on  the  cone  and 
expanded  equally  from  both  sides. 

Bolts  are  made  in  three  different  ways,  i.  e.,  by  forging, 
upsetting,  or  welding.  The  first  of  these  methods  is  ordinarily 
used  for  special  bolts  and  those  that  are  to  be  finished  or 
turned  to  size.  Such  bolts  are  forged  from  stock  having  a 
diameter  equal  to  that  of  the  head,  and  are  therefore  the 
strongest  kind  made.  The  second  method,  in  which  the  stock 
is  upset  to  form  the  head,  is  the  one  most  commonly  used  for 
both  hand-  and  machine-made  bolts.  In  the  third  method  the 
head  is  formed  by  welding  a  ring  of  stock  around  the  stem. 
If  equally  well  made,  an  upset-head  bolt  is  stronger  than  a 
welded-head  bolt. 

The  size  of  a  bolt  is  given  by  the  diameter  and  length  of 
the  shank.  Thus  a  1  x  12-inch  bolt  means  one  with  a  shank  1 


Project  16. 


Plate  XVII. 


BAND    RING 


Stock.  £"x  1^x13  g"  WroT  Iron 


© 


© 


Hil" 


72 


UPSET-HEAD   BOLT  73 

inch  in  diameter  and  12  inches  long  from  the  under  side  of  the 
head  to  the  end.  The  dimensions  of  a  bolt-head  are  governed 
by  the  diameter  of  the  shank,  and  are  entirely  independent  of 
the  length.  For  square  and  hexagonal  bolt-heads,  the  distance 
across  the  flats  is  equal  to  1^  times  the  diameter  of  the  shank 
plus  l/s  inch,  and  the  thickness  of  the  head  is  equal  to  the 
diameter  of  the  shank.  Thus  a  1-inch  bolt  should  have  a  head 
1>2  X  1  +  y&,  or  15/s  inches  across  the  flats,  and  1  inch  thick. 
These  are  the  dimensions  for  rough  heads,  each  dimension  for 
a  finished  head  being  -^  inch  less  than  for  a  rough  head. 

Heading-Tool. — For  squaring-up  the  under  side  of  the 
head  on  a  bolt,  a  heading-tool  (Fig.  36)  is  required.  In  use 
this  is  placed  on  the  face  of  the  anvil,  so  that  while  the  head 
of  the  bolt  is  being  forged  the  shank  can  project  down  thru 
the  heading-tool  and  the  hardie-tool.  The  hole  in  this  tool 
should  be  slightly  larger  than  the  stock  for  which  it  is  in- 
tended, in  order  that  a  shank,  when  heated,  may  drop  thru  it 
easily.  For  this  reason  a  different  heading-tool  is  required 
for  each  size  of  round  stock  used. 


Fig.  36.  Fig.  37. 

HEADING-TOOL.  CUPPING-TOOL. 

Cupping-Tool. — Bolt  heads  generally  have  the  top  corners 
rounded,  or  chamfered.  This  is  ordinarily  done  with  a  cup- 
ping-tool (Fig.  37),  but  a  top-swage,  or  a  hand-hammer  may 
be  used. 

Project  17.    Upset-Head  Bolt.     (Plate  XVIII.) 

STEP  ONE. — Cut  the  stock  to  length,  and  square'  both  ends. 
Heat  one  end  for  about  2  inches  to  a  yellow  heat.  Place  the 


Project  17. 


Plate  XVIII. 


UPSET  HEAD  BOLTS 

Stock  for  square  head  bolt:  4- x  9?  round  machine  steel 


—  Upset  to  7f  — 


2 a)     S  Heading  tool 


I 


5a 


IT 

•LJJL 


Stock  for  hexagonal  head  bolt:  4  x9"  round  machine  steel 


.U 


i« 


© 


td 


74 


WELDED-HEAD  BOLT  75 

hot  end  on  the  face  of  the  anvil,  holding  the  piece  vertically 
with  a  pair  of  link-tongs,  and  strike  on  the  cold  end  with  a 
heavy  hand-hammer.  Care  .should  be  taken  to  keep  the  stock 
straight  while  upsetting. 

STEP  Two. — Bring  the  upset  end  to  a  high  heat,  and  insert 
the  shank  in  a  heading-tool.  Form  the  head  by  flattening  the 
upset  portion,  as  shown  at  2.  To  aid  in  keeping  the  shank  at 
the  center  of  the  head,  a  circle  with  a  radius  about  ^  inch 
greater  than  that  of  the  hole  should  be  drawn  with  chalk  on 
the  face  of  the  tool.  The  student  can  then  tell  when  one  side 
of  the  head  is  out  too  far. 

STEP  THREE. — Forge  the  head  square  or  hexagonal  on  the 
face  of  the  anvil.  Insert  the  shank  in  a  heading-tool  and 
chamfer  the  top  corners  with  a  cupping-tool.  The  shank 
should  be  finished  between  top-  and  bottom-swages. 

Project  18.     Welded-Head  Bolt.     (Plate  XIX.) 

STEP  ONE. — If  a  piece  of  stock  the  required  size  is  not 
available,  draw-out  a  large  piece  to  the  size  shown  at  1. 

STEP  Two. — Cut  off  the  end  at  an  angle  on  the  hardie,  and 
make  another  cut  half-way  thru  the  stock  at  the  point  indi- 
cated. 

STEP  THREE. — Bend  the  drawn-out  portion  over  the  horn 
as  shown  at  3. 

STEP  FOUR. — Break  off  the  bent  portion,  and  finish  the 
bending  over  a  piece  of  cold  %-inch  round  stock.  This  collar 
should  then  be  hammered  approximately  square,  and  made  to 
appear  as  shown  at  4.  If  it  were  made  round,  the  joint  might 
show  on  one  side  when  finished,  making  a  poorly  appearing 
head. 

STEP  FIVE. — Bring  one  end  of  the  shank  to  a  welding  heat, 
and  upset  it  in  the  cold  collar,  as  at  5.  Before  starting  to 
weld  it  be  sure  that  the  shank  will  slip  thru  the  heading-tool. 


Projects  18  and  19. 


Plate  XIX. 


WELDED    HEAD    BOLT 

Stock    for    collar  :    |"  round    Wrot  Iron 


j 


© 


Stem    of  bolt:    6|"xf"  round    Wrot    Ir 


YA' 


® 


^ 


set  stem    on    cold     collar 


FORGED     BOLT 


© 


© 


Center  punch1', 
Chisel    mark 


1  r 


A  bottom  fullers 

s~*\ 


76 


FORGED  BOLT  77 

STEP  Six. — Heat  the  head  slowly,  to  prevent  the  collar 
from  burning,  and  weld  it  by  hammering  on  all  four  sides. 
Finish  it  in  a  heading-tool  in  the  same  manner  as  an  upset 
head. 

If  there  is  too  much  stock  on  the  bolt  head,  forge  it  to  the 
proper  size  across  the  flats,  and  cut  the  surplus  stock  off  of 
the  end  with  a  hot  eye-chisel. 

Project  19.     Forged  Bolt.     (Plate  XIX.) 

It  is  necessary  for  two  students  to  work  together  on  this 
.exercise,  so  a  piece  of  stock  long  enough  to  make  two  bolts 
should  be  used. 

STEP  ONE. — Cut  the  stock  to  length,  and  mark  it  with  a 
center-punch  and  a  chisel  as  indicated. 

STEP  Two. — Fuller  one  end,  as  shown  at  2. 

STEP  THREE. — Draw-out  the  end  A  to  size  under  a  trip- 
hammer. 

STEP  FOUR. — Fuller  and  hammer  out  the  other  end  in  the 
same  manner. 

STEP  FIVE. — Cut  the  stock  thru  the  center  along  the  dotted 
line.  Reheat,  and  insert  the  shank  of  one  end  in  a  heading- 
tool,  finishing  the  head  in  the  same  manner  as  the  upset  head. 

The  shank  and  under  side  of  the  head  of  a  forged  bolt  are 
generally  turned  to  the  finished  size  in  the  machine  shop.  In 
some  cases,  however,  such  bolts  are  forged  to  the  required 
sizes,  so  that  no  machine  work  is  necessary. 


CHAPTER  IV. 
SPECIAL  WELDS. 

The  Butt  Weld  is  made  by  rounding  the  ends  of  two  pieces 
of  stock  and  driving  them  together  at  a  welding  heat,  as  shown 
in  Fig.  38.  The  purpose  in  rounding  the  ends  is  to  permit 
squeezing  the  molten  oxide  out  of  the  joint.  If  they  were 
concave,  impurities  would  be  held  between  the  two  pieces, 
making  an  unsound  weld. 

When  the  pieces  of  stock  are  short  the  butting,  or  weld- 
ing, is  generally  done  on  the  anvil,  but  with  long  pieces  it  is 
done  in  the  fire.  Long  pieces  are  placed  end  to  end  in  the  fire, 
and  when  the  welding  heat  has  been  reached  they  are  driven 
together.  In  doing  this  the  blacksmith  holds  one  of  them  to 
steady  it,  while  the  helper  strikes  on  the  projecting  end  of  the 
other.  When  the  pieces  are  stuck  together  the  resulting  bar 
is  removed  from  the  fire,  and  hammered  to  size  on  the  anvil. 
It  is  then  smoothed  between  top-  and  bottom-swages. 


•    Fig.  38.     BUTT- WELD. 

A  butt  weld  may  be  used  on  Ij4-inch  stock  or  larger.  It  is 
not  as  safe  or  as  strong  as  a  lap  weld,  but  has  the  advantage 
of  requiring  no  upsetting  and  scarfing  of  ends.  All  the  up- 
setting necessary  occurs  during  the  welding  process. 

V-Weld. — Another  weld  suitable  for  large-sized  stock  is 
the  V-weld.  The  ends  of  the  stock  are  first  cut  with  a  hot 
chisel  to  the  form  shown  in  Fig.  39.  The  pieces  are  then 
placed  end  to  end  in  the  fire  and  heated.  The  square  end  of 
the  short,  chisel-pointed  piece  should  project  over  the  edge  of 
the  forge.  When  the  stock  is  at  the  welding  heat,  this  end  is 
struck  with  a  backing-hammer  or  a  sledge,  depending  on  the 

78 


JUMP  WELD 


79 


size  of  the  stock.  This  upsets  and  welds  the  ends  together. 
The  joint  is  then  hammered  to  size  and  swaged  on  the  anvil. 
The  V-Weld  is  suitable  for  welding  round  or  square  steel 
and  wrought  iron.  Besides  being  easy  to  make,  on  account 
of  the  elimination  of  upsetting  and  scarfing,  it  forms  an  ex- 


Fig.  38.     V-WELD. 

tremely  strong  joint.  It  is  not  suitable  for  stock  less  than 
\l/2  inches  in  diameter,  as  smaller  stock  bends  while  the  pieces 
are  being  driven  together  in  the  fire. 

The  Jump  Weld  is  one  ordinarily  used  by  shipsmiths  on 
marine  or  ship  work.  Its  applications  are  numerous,  but  its 
main  principle  is  the  joining  of  one  end  of  round,  square,  or 
rectangular  stock  to  some  point  on  the  side  of  a  piece  of  stock 
of  the  same  or  of  a  different  size. 

In  making  the  "jump,"  shown  at  A  in  Fig.  40,  the  end  of 
the  stock  is  brought  to  the  welding  heat  and  hammered  on  the 


Fig.  40.    JUMP  WFXD. 

sides,  to  prevent  it  from  bursting  while  -scarfing  it.  If  the 
piece  is  a  short  one,  the  scarfing  may  be  done  by  standing  it 
on  end  on  the  anvil  and  hammering  the  hot  end  so  as  to  form 
a  flange,  similar  to  the  one  shown  at  A. 


80  SPECIAL  WELDS 

If  this  piece  is  to  be  "jumped,"  or  welded,  to  a  piece  of 
flat  stock,  the  latter  must  be  made  thicker,  where  the  joint  is  to 
be,  in  order  to  allow  for  hammering.  This  can  be  done  either 
by  upsetting  the  flat  stock  or  by  forging  it  from  a  thicker 
piece.  An  indentation  is  made  at  this  point  with  a  bob-punch, 
as  shown  at  B,  to  accommodate  the  flanged  end  on  the 
"jump." 

The  two  pieces  are  generally  brought  to  the  welding  heat 
in  separate  fires.  The  flat  piece  is  then  placed  on  the  anvil 
and  the  "jump"  in  position  on  it.  The  end  of  the  "jump"  is 
struck  with  a  sledge,  and  the  flange  quickly  welded  down  with 
a  top-fuller,  making  the  joint  appear  as  shown  at  C,  Fig.  40. 

The  Split  Weld  is  used  for  welding  together  the  ends  of 
thin  stock,  such  as  brake-bands  and  sheet  steel.  If  an  ordi- 
nary lap  weld  were  used  for  this  purpose,  the  time  lost  in  get- 
ting the  scarfed  ends  in  position  for  welding  would  permit 
thin  stock  to  cool,  making  welding  difficult :  With  the  split 
weld  the  scarfs  are  in  position  when  placed  on  the  anvil,  and 
may  be  hammered  together  immediately. 


Fig.  41.     SPLIT  WELD. 

The  ends  of  the  pieces  to  be  joined  are  upset  and  scarfed 
or  tapered  to  a  blunt  edge.  They  are  then  split  down  the  cen- 
ter, as  shown  at  A,  Fig.  41,  for  a  distance  depending  on  the 
thickness  of  the  stock,  but  ordinarily  about  ty  inch.  One-half 
of  each  end  is  bent  up  and  the  other  half  down,  as  at  A.  The 
ends  are  then  heated,  pushed  tightly  together,  and  closed  down 


SPLIT   WELD 


81 


on  each  other,  as  shown  at  B  in  Fig.  41.    The  welding  is  done 
in  the  regular  way. 

Split  Weld  for  Heavy  Stock. — A  split  weld  suitable  for 
heavy  stock  is  shown  in  Fig.  42.  In  making  this  weld  the 
ends  of  the  pieces  are  upset  and  scarfed,  as  at  A,  one  end 


Fig.  42.     SPLIT  WELD  FOR  HEAVY  STOCK. 

being  pointed  and  the  other  split  and  shaped  like  a  Y.  The 
pieces  are  then  driven  together  and  closed  down,  one  on  the 
other,  ready  for  welding,  as  shown  at  B,  Fig.  42. 


C  D 

Fig.  43.    WELDING  TIP  ON  A  PICK. 

This  weld,  or  one  very  similar  to  it,  is  often  used  when 
welding  tool  steel  to  iron  or  to  machinery  steel.  An  example 
of  this  is  the  "steeling"  of  the  Norway  iron  body  of  a  pick, 
shown  at  A,  Fig.  43.  The  ends  of  this  body  are  split  and 
shaped  as  shown  at  B.  The  piece  to  be  welded  on  is  about 
Y-Z  x  1  inch  and  from  4  to  5  inches  long.  It  is  pointed  and 


82  SPECIAL  WELDS 

notched  with  a  chisel,  as  at  C,  to  prevent  it  from  falling  out 
while  heating.  The  two  pieces  are  then  driven  together  and 
the  ends  of  the  Y  closed  down,  as  shown  at  D.  They  are 
heated  slowly,  to  prevent  the  tool  steel  from  being  burned, 
and  welded  under  a  trip-hammer  or  with  a  sledge.  The  end 
of  the  pick  is  drawn  to  a  point  under  the  trip-hammer,  and 
made  smooth  'with  a  flatter.  It  is  then  reheated,  hardened, 
and  the  temper  color  drawn  to  a  dark  blue. 

Project  20.    T-Weld.     (Plate  XX.) 

STEP  ONE. — Cut  off  a  piece  of  stock  for  the  leg  of  the  T, 
and  upset  it  as  shown. 

STEP  Two. — Start  the  scarf  with  the  hand-hammer,  as 
at  2. 

STEP  THREE. — Bring  the  "scarf  to  the  form  shown  at  3 
with  a  J^-inch  top-fuller. 

STEP  FOUR. — Finish  this  scarf  with  the  same  fuller,  then 
smooth  it  with  a  hand-hammer. 

STEP  FIVE. — Upset  the  cross-piece  at  the  center,  as  shown 
at  5. 

STEP  Six. — Form  the  scarf  as  at  6  with  the  bob-punch  of 
Fig.  16.  This  can  be  done  by  using  the  peen  of  a  hand-ham- 
mer and  striking  on  its  face  with  a  heavier  hammer;  but  it  is 
rather  dangerous,  as  the  face  of  the  hand-hammer  is  liable  to 
break  unless  the  heavier  hammer  is  wielded  by  an  expert. 

STEP  SEVEN. — Bring  the  scarfed  portions  of  the  two  pieces 
to  the  welding  heat  and  weld  them,  using  a  hammer  to  stick 
them  together  and  a  necking-tool  or  fuller  to  weld  down  the 
edges  of  the  scarf.  In  removing  the  pieces  from  the  fire  for 
welding,  the  cross-piece  should  be  taken  in  the  right  hand 
and  the  other  piece  in  the  left.  This  leaves  the  right  hand 
free  for  kammering  after  the  pieces  have  been  placed  in  po- 
sition. A  student  should  practice  putting  the  pieces  together 
while  cold  before  attempting  to  weld  them. 

After  the  welding  "has  been  finished  the  stock  should  be 


Project  20. 


Plate  XX. 


T  WELD 


Stock:  1  piece 


piece  |"x9"  long     Wrot  Iron 


I a j 

CZ  _9-_        -— ^ 


©  [ 


Upset  to  7— 


o 

© 


m         I " 

rr  ._7i-_ 4  i 


© 


Section  through  A  A. 


83 


84  SPECIAL  WELDS 

smoothed  between  top-  and  bottom-swages,  and  the  scale  re- 
moved with  a  file.  The  ends  are  then  trimmed  off,  making 
the  dimensions  of  the  T  as  shown  at  7. 

With  flat  stock  the  scarfs  for  a  T-weld  are  made  in  the 
same  manner. 

Project  21.    Angle  Weld.     (Plate  XXI.) 

STEP  ONE. — Cut  and  upset  the  short  piece  for  the  angle  to 
the  size  shown  at  1.  Since  the  stock  has  to  be  upset  for  a  con- 
siderable distance  from  the  end,  the  tip  should  be  partially 
cooled  in  water  to  prevent  the  upsetting  from  taking  place 
mostly  at  that  point. 

STEP  Two. — Scarf  this  piece  with  a  bob-punch  or  the  peen 
of  a  hammer,  as  shown  at  2.  The  length  of  this  scarf  should 
be  slightly  less  than  the  width  of  the  one  on  the  other  piece, 
so  that  the  lip  A  (4)  will  lap  over  on  the  thick  portion  of  the 
stock. 

STEP  THREE. — Cut  and  upset  the  other  piece  to  the  form 
shown  at  3. 

STEP  FOUR. — Start  the  scarf  on  this  piece  in  the  same 
manner  as  for  the  flat  lap  weld.  It  should,  however,  be  al- 
lowed to  widen  out,  in  order  to  furnish  material  for  the  lip  A, 
which  is  made  by  placing  the  stock  on  edge  on  the  anvil  with 
the  scarf  projecting  over  the  rounded  edge  and  hitting  the 
upper  edge  with  a  hand-hammer.  The  top  edge  should  then 
appear  straight,  as  shown. 

STEP  FIVE.— After  bringing  the  two  scarfed  ends  to  a 
welding  heat  remove  the  pieces  from  the  fire,  holding  the 
short  one  (2)  in  the  right  hand  and  the  long  one  (4)  in  the 
left.  Weld  the  joint  with  a  heavy  hand-hammer,  and  finish  it 
with  a  flatter.  The  scale  should  then  be  removed  with  a  file, 
and  the  ends  cut  off  to  length  with  a  hot  chisel. 


Project  21. 


Plate  XXI. 


ANGLE  WELD 


Stock  ;  |"x  1?"  Wrot  iron 


© 


© 


Upset  from  5i"to4i 


~nr«. 


®   c 


(B) 


li 
!L 


li  —  H      Upset  from  8  to  7  1 


^J 


j._ 


Cut  to  size,-" 


85 


CHAPTER  V. 
HAMMER  WORK. 

In  making  forgings  larger  than  the  projects  previously  de- 
scribed in  this  book,  some  type  of  power  hammer  is  invari- 
ably used.  Those  commonly  found  in  technical  schools  are 
the  trip-  or  belt-hammer  and  the  steam-hammer. 

The  Trip-  or  Belt-Hammer  (Fig.  44)  is  used  for  hammer- 
ing medium  or  small-sized  forgings.  Its  size  is  designated  by 
the  weight  of  the  falling  parts,  i.  e.,  in  a  125-pound  hammer 
the  combined  weight  of  the  falling  parts  is  125  pounds. 

The  frame  of  the  machine  surrounds  the  anvil,  or  die 
block,  B,  but  the  two  are  usually  mounted  on  separate  foun- 
dations. This  is  done  so  that  the  continual  use  of  the  ham- 
mer will  not  have  a  tendency  to  break  the  frame,  and  also  in 
order  to  permit  adjustment  of  the  position  of  the  lower  die. 

This  type  of  hammer  is  belt  driven,  the  blows  being  reg- 
ulated by  means  of  the  foot-treadle,  T.  This  gives  very  good 
control  of  the  hammer  except  at  starting,  when  the  blows  are 
sometimes  rather  jerky.  As  hammering  continues  the  blows 
become  more  uniform.  A  student  should  receive  special  in- 
structions in  the  manipulation  of  a  trip-hammer  before  start- 
ing to  use  it. 

When  drawing-out  stock  with  a  trip-hammer  the  material 
should  be  placed  at  the  center  of  the  dies.  If  it  is  placed  at 
one  side  there  will  be  an  undue  stress  on  the  springs,  and  they 
will  be  likely  to  break. 

Hollow-bit  tongs  are  generally  used  for  holding  work  at 
the  power-hammer,  as  a  firm  grip  can  be  obtained  with  them 
on  either  round,  square,  or  flat  material.  Flat-jawed  tongs 
should  not  be  used,  as  they  give  a  very  poor  grip  when  the 

86 


POWER-HAMMERS 


87 


jaws  are  in  the  vertical  position.  To  maintain  a  firm  grip,  a 
link  should  be  slipped  over  the  handles  of  the  tongs,  so  as  to 
hold  them  close  together. 

A   trip-hammer   may   also    be   employed    for   making   drop 
forgings  by  using  special  dies  that  may  be  made  of  cast  iron. 


Fig.  44.    TRIP-HAMMER.  Fig.  45.    STEAM-HAMMER. 

This  type  of  hammer  has  the  advantage  over  a  steam- 
hammer  in  the  matter  of  lower  first  cost  and  great  economy 
in  operation.  It  is  not,  however,  so  well  suited  to  very  heavy 
work. 

The  Steam-Hammer  is  generally  made  in  larger  sizes  than 


88  HAMMER  WORK 

the  trip-hammer,  the  combined  weight  of  the  falling  parts 
ranging  from  a 'few  hundred  to  several  thousand  pounds.  A 
500-pound  hammer  is  shown  in  Fig.  45. 

As  the  name  implies,  this  hammer  is  driven  by  steam.  The 
latter  enters  at  the  top  of  the  cylinder,  C,  and  forces  down  the 
ram,  R.  The  blow  is  controlled  and  regulated  by  means  of  the 
levers,  A  and  E,  which  are  operated  by  an  assistant.  If  the 
blacksmith  works  alone,  the  hammer  may  be  controlled  by 
means  of  the  foot-treadle. 

The  ram,  R,  and  the  dies,  D,  are  generally  placed  at  an 
angle  of  45°  with  the  front  of  the  frame.  This  permits  the 
hammering  of  material  either  across  or  lengthwise  on  the  die 
without  interference.  As  with  the  trip-hammer,  the  die-block, 
B,  rests  on  a  separate  foundation  from  that  of  the  frame. 

Finishing  Allowance. — Forgings  made  under  a  hammer 
are  often  machined  and  finished  to  size.  For  this  reason  a  cer- 
tain allowance  should  be  made  for  finishing  them.  The 
amount  of  this  allowance  varies  from  y%  inch  on  small  forg- 
ings  to  24  inch  on  large  ones.  Take  as  an  example  a  shaft 
which  is  to  be  finished  8  inches  in  diameter.  It  should  be 
forged  to  a  diameter  of  from  8%  to  8^4  inches. 

Project  22.  Forged  Open-End  Wrench.  (Plates  XXII 
and  XXIII.) 

When  making  this  project  it  is  necessary  for  two  students 
to  work  together,  as  it  is  inconvenient  to  make  such  a  wrench 
alone.  Considerable  time  will  also  be  saved  in  this  way. 

STEP  ONE. — Cut  off  a  piece  of  machine  steel  to  the  size  in- 
dicated, and  mark  it  with  a  center-punch,  as  shown  at  1.  A 
piece  4fys  inches  long  would  be  enough  to  make  this  wrench, 
but  it  would  be  hard  to  hold  while  being  worked  under  a  trip- 
hammer, as  the  tongs  would  become  hot  and  afford  a  poor 
grip.  There  should  be  enough  of  a  tong  hold  to  prevent 


Project  22. 


Plate  XXIII. 


FORGED    OPEN   END  WRENCH -Corn-. 


Cut  off  along 
dotted  line  in 
(5)  then  cut 
corners  as 
shown 


© 


Enlarqe  hole 


10)  Finish  with  file 


X~> 

Punch  |  hole  hQs 


Project  22. 


Plate  XXII. 


FORGED    OPEN   END    WRENCH 

Stock t&lJxQj?  machine   steel 


© 


® 


i_ gl" 


W 


Center  punch 
marks  for 
fullering 

Use  i"  top  and 
bottom  fullers 


ra 


About  £ 


.-*-. 


90 


OPEN-END  WRENCH  91 

the  jaws  of  the  tongs  from  being  caught  between  the  dies. 
It  is  therefore  best  to  use  a  piece  of  stock  9l/2  inches  long. 
This  will  give  enough  material  for  two  wrenches,  with  an 
allowance  for  a  short  tong  hold.  Remember  to  use  hollow-bit 
tongs.  Flat- jawed  tongs  are  unsafe. 

If  both  handles  are  to  be  drawn  out  before  cutting  the  stock 
along  the  dotted  line  at  3,  do  not  allow  material  for  tong  hold. 
In  such  case  cut  a  piece  8^4  inches  long. 

STEP  Two. — Use  y2-'mch  top-  and  bottom-fullers  to  make 
the  grooves  shown  at  2.  To  insure  uniformity  in  the  depth  of 
these  marks  the  stock  should  be  turned  over  several  times 
when  fullering. 

STEP  THREE. — Draw-out  the  handle  under  the  trip-ham- 
mer, leaving  it  wider  than  the  finished  size,  to  allow  for  swag- 
ging  the  edges. 

STEP  FOUR. — Use  ^-inch  top-  and  bottom-fullers  on  the 
other  end,  as  shown  at  4. 

STEP  FIVE. — Draw-out  this  end  to  provide  for  a  tong  hold 
when  making  the  second  wrench. 

STEP  Six. — Cut  off  the  stock  with  a  hot  chisel  along  the 
dotted  line  shown  at  5.  The  corners  should  then  be  cut  off  to 
facilitate  rounding  the  head. 

STEP  SEVEN. — Round  the  head  by  placing  it  on  a  l^-inch 
bottom-swage  and  using  a  1-inch  top-fuller  on  the  neck  or 
fillet.  A  set-hammer  or  a  %  -inch  top-fuller  can  be  used  for 
rounding  the  circular  part  adjacent  to  the  handle.  Finish 
shaping  with  a  hand-hammer,  leaving  the  head  %  inch  thick. 

STEP  EIGHT. — Punch  a  ^-inch  hole  thru  the  head  at  the 
center-punch  mark  shown  at  7. 

STEP  NINE. — Enlarge  thisj  hole  to  %-inch  diameter  by 
driving  in  a  drift-pin.  If  when  doing  this  the  stock  becomes 
thinner  at  one  side,  that  side  should  be  cooled  before  enlarg- 
ing the  hole  further.  This  equalizes  the  thickness  of  the 
stock  around  the  hole.  Thin  the  head  with  a  flatter  to  T%  inch. 

STEP  TEN. — Place  a  suitable  sheet-iron  template  on  top  of 


92  HAMMER  WORK 

the  project,  and  mark  with  a  cold  chisel  the  lines  for  the 
opening  in  the  head,  as  shown  by  the  dotted  lines  at  9.  These 
marks  should  make  an  angle  of  15°  with  the  handle  of  the 
wrench.  The  opening  in  the  head  is  then  cut  with  a  hot  chisel 
and  the  head  hammered  so  as  to  make  it  Y-Z  inch  thick. 

Square  the  inside  of  the  jaws  on  a  saddle,  as  shown  in 
Fig.  46.  If  the  ends  are  too  long  they  should  be  cut  to  the 
correct  length  on  the  saddle,  in  order  to  prevent  them  from 
becoming  too  thin. 

Finish  the  edges  of  the  handle  between  ^2 -inch  top-  and 
bottom-swages  and  the  faces  with  a  flatter.  After  the  wrench 
has  cooled  the  inside  of  the  jaws  should  be  filed  to  fit  a  nut. 
The  wrench  is  then  case-hardened,  as  described  in  Chapter  VI. 


Fig.  46. 

Project  23.   Flat-Jawed  Tongs.    (Plates  XXIV-XXV.) 

STEP  ONE. — Cut  a  piece  of  machine  steel  for  the  jaws, 
and  mark  it  as  shown  at  1.  For  tongs  without  welds,  cut 
stock  16  inches. 

STEP  Two. — Heat  one  end  and  place  it  on  the  anvil  with 
the  center-punch  mark  at  the  rounded  edge,  as  shown  in  Fig. 
A.  Hammer  it  as  indicated,  gradually  raising  the  cold  end 
until  it  is  parallel  with  the  face  of  the  anvil,  as  shown  by  the 
dotted  lines.  This  forms  the  shoulder,  shown  at  2.  If  the 
stock  were  held  flat  on  the  anvil  when  starting  this  shoulder, 
it  would  probably  move  forward  after  each  blow,  thus  making 
the  shoulder  a  poor  one. 


FLAT-JAWED  TONGS  93 

STEP  THREE. — Give  the  stock  a  quarter  turn  to  the  left, 
and  place  it  on  the  anvil  as  shown  in  Fig.  B.  Hammer  out 
the  stock  for  the  eye,  taking  care  to  have  the  blows  fall  di- 
rectly above  the  edge  of  the  anvil.  This  is  done  to  prevent  the 
jaw  from  bending  upward  while  hammering. 

When  placing  the  stock  on  the  anvil  for  hammering  the 
eye,  it  should  never  be  turned  to  the  right.  This  would  make 
the  tongs  left-handed.  In  the  finished  tongs  the  handle  of  the 
top  jaw  should  look  toward  the  right. 

STEP  FOUR. — With  a  ^-inch  top-  or  bottom-fuller  make  a 
mark  as  shown  at  4.  Form  the  second  jaw  on  the  other  end 
of  the  stock  in  the  same  manner.  The  stock  should  then  be 
cut  through  the  center  at  the  chisel  mark,  as  shown  at  4  in 
Plate  XXVI. 

STEP  FIVE. — Draw-out  the  stub  end  (to  which  the  handle 
is  to  be  welded)  on  the  anvil,  and  scarf  it,  as  shown  at  5. 
Several  cuts  should  be  made  on  the  face  of  the  scarf  with  a 
hardie,  to  prevent  the  pieces  from  slipping  apart  when  welding. 

STEP  Six. — Cut  a  piece  of  stock  long  enough  to  make  both 
handles,  and  upset  it  at  the  ends,  as  shown  at  6. 

STEP  SEVEN. — Scarf  the  ends  of  this  piece  as  shown.  If 
this  stock  is  also  of  machine  steel,  the  scarfs  must  be  nicked 
in  the  same  manner  as  those  on  the  jaws. 

STEP  EIGHT. — Weld  the  jaws  on  the  end3  of  this  piece, 
then  cut  it  at  the  center.  Finish  the  portion  of  the  handle 
near  the  eye  with  a  flatter.  Round  the  eye  on  the  horn  of  the 
anvil  with  a  J^-inch  top-fuller,  as  shown  in  Fig.  C.  Finish 
hammering  the  jaw  to  size,  and  make  a  groove  thru  the  center 
with  a  2^-inch  top-fuller.  This  groove  enables  one  to  hold 
round  stock  with  these  tongs.  It  also  insures  a  better  grip  on 


Project  23. 


Plate  XXIV. 


FLAT  JAWED  TONGS. 


Stock-  f  '*  5x8'  machine  steel  for  jaws. 

i'x  25*" round  machine  steel  or  W.I. for  handles. 


Fig.D. 


94 


LINK  TONGS  95 

flat  material,  since  both  sides  of  the  jaws  grip  firmly.  With- 
out the  groove  the  jaws  might  touch  the  stock  at  the  center 
only.  A  series  of  cross  cuts,  as  shown,  should  be  made  with 
a  hot  chisel,  to  produce  a  still  firmer  hold. 

STEP  NINE. — Punch  the  rivet  hole  shown  at  9  so  that  a 
^-inch  rivet  will  easily  drop  into  the  hole.  Bring  the  straight 
end  of  the  rivet  to  a  high  heat  and  insert  it  in  the  holes  in  the 
two  eyes.  Turn  the  tongs  over  and  place  the  rivet  head  on  a 
bottom  snap  as  shown  in  Fig.  D.  Head  the  heated  end  of 
the  rivet  by  first  giving  it  a  few  blows  with  the  face  of  a  hand- 
hammer,  then  rounding  it  with  the  peen  of  the  hammer,  and 
finally  smoothing  it  with  the  top  snap,  or  riveting  tool. 

After  riveting,  the  tongs  will  be  stiff  and  will  not  open. 
This  should  be  remedied  by  heating  them  at  the  rivet  and 
opening  and  shutting  them  several  times.  Finish  the  tongs 
by  fitting  them  to  the  stock  on  which  they  are  to  be  used; 

Project  24.    Link  Tongs.     (Plates  XXVI-XXVII.) 

STEPS  ONE  TO  SEVEN  are  the  same  as  for  the  flat-jawed 
tongs. 

STEP  EIGHT. — Weld  on  the  handles  in  the  same  manner  as 
before.  Draw-out  the  jaws,  and  finish  them  with  a  flatter  to 
the  form  shown  at  8.  Cut  off  their  ends  with  a  hardie,  as 
shown. 

STEP  NINE.— Punch  the  holes  for  a  ^-inch  rivet,  and  bend 
the  ends  of  the  jaws  over  the  rounded  edge  of  the  anvil  to  the 
form  at  9. 

STEP  TEN. — Finish  bending  the  jaws  over  the  horn  of  the 
anvil.  This  bending  may  also  be  done  with  a  bottom-swage 
and  a  top-fuller. 

STEP  ELEVEN.— Rivet  the  parts  together,  and  finish  the  tongs 
in  the  same  manner  as  the  flat- jawed  tongs. 


Project  23. 


Plate  XXV. 


FLAT  JAWED  TONGS- CONT. 


® 


5tod<-ix25i"round  machine  steel. 


fuller  to  ho/4  £  'roan*  s/ocJ< 


96 


Project  24. 


Plate  XXVI. 


LINK  TONGS. 


© 


Stock-  fxi'x7 "machine  steel  for  jaws. 

t"x  E5?"  round  mack  steel  or  W  I.  for  handles. 


r 


AM**** 

afonn/ 


® 


h— *--H 


® 


j 


Fig.  C 
/y/i/5/7  riveting 


97 


Project  24. 


Plate  XXVII. 


LINK  TONGS -CONT. 


Srock-s'x  25s" round  much,  sleel  or  W.I 


JL 


Punch  ho/e  for  ffof  rrrefj 


® 


98 


HOLLOW-BIT  TONGS  99 

Project  25.    Hollow-Bit  Tongs.   (Plate  XXVIII.) 

One  of  the  methods  used  for  making  hollow-bit  tongs  is 
shown  in  Plate  XXVIII.  A  student  who  has  made  the  major- 
ity of  the  preceding  projects  should  be  able  to  make  a  pair  of 
these  tongs  without  a  detailed  explanation  of  the  various 
steps.  However,  the  following  points  should  be  noted : 

At  3  the  stock  for  the  jaw  is  shown  fullered  and  ready  for 
shaping  to  size.  It  should  be  flattened  and  brought  to  the  de- 
sired form  with  a  square-edge  set-hammer.  The  object  of  the 
fuller  marks  is  to  leave  the  neck  thick,  thereby  making  a 
stronger  jaw. 

Enough  stock  is  provided  in  this  exercise  for  drawing-out 
the  handles.  This  is  done  under  the  trip-hammer.  The  han- 
dles are  then  rounded  between  top-  and  bottom-swages. 

The  flat  end,  or  jaw  proper,  is  bent  to  the  form  at  5  by 
placing  it  on  a  V-block  and  using  a  top-fuller  on  the  inside, 
as  shown  in  Fig.  A. 

To  bend  the  stock  between  the  jaw  proper  and  the  eye  to 
the  form  shown  at  7,  place  it  over  the  rounded  edge  of  the 
anvil  and  use  a  1-inch  top-fuller  on  it,  as  shown  in  Fig.  B. 

After  riveting  the  tongs,  they  should  be  fitted  to  a  piece  of 
square  stock  of  the  size  on  which  they  are  to  be  used. 


Project  25. 


Plate  XXVIII. 


HOLLOW    BIT  TONGS 


Stock:  |  x  10^    Round    Machine    Steel 

3F  © 


© 


100 


CHAPTER  VI. 
ANNEALING,  HARDENING  AND  TEMPERING  STEEL. 

Annealing. — When  carbon  steel  is  heated  to  a  temperature 
of  about  1400°  F.  and  allowed  to  cool  slowly,  it  becomes  soft, 
or  annealed.  The  more  slowly  it  is  cooled  the  softer  it  is 
when  cold. 

There  are  two  objects  in  annealing:  first,  to  soften  the 
metal,  and  second,  to  remove  internal  stresses.  For  instance, 
a  piece  of  tool  steel  is  generally  softened  or  annealed  before 
being  worked  in  a  lathe  or  otherwise  machined. 

The  common  method  of  annealing  tool  steel  is  to  heat  it 
to  a  cherry-red  and  bury  it  in  ashes  or  slaked  lime  until  it  has 
entirely  cooled.  Care  must  be  taken  not  to  heat  the  steel  too 
much,  or  its  grain  will  become  coarse  and  the  steel  weakened. 
The  ashes  and  lime  used  should  be  perfectly  dry,  so  that  they 
will  be  poor  conductors  of  heat  and  cause  the  steel  to  cool 
slowly. 

Box  Annealing. — In  annealing  a  large  number  of  steel 
pieces,  they  are  usually  packed  with  ground  bone  or  fine  char- 
coal in  cast-iron  boxes  and  placed  in  an  annealing  furnace. 
When  they  have  reached  the  proper  temperature  the  draft  is 
shut  off,  and  the  furnace  is  allowed  to  cool  slowly.  The  steel 
is  not  removed  from  the  boxes  until  it  is  cold. 

This  method  of  annealing  prevents  the  steel  from  being 
covered  with  scale,  because  no  air  is- admitted  and  the  oxygen 
of  the  air  in  the  boxes  is  consumed  by  the  red-hot  carbon. 

Water  Annealing. — The  quickest  method  of  annealing 
steel  is  known  as  "water  annealing."  It  will  not  leave  the 
steel  as  soft  as  when  cooled  slowly  in  lime  or  ashes,  but  it 
often  serves  the  purpose  more  conveniently.  A  case  in  which 
this  would  be  so  is  when  a  drill  or  tap  has  broken  off  in  a 
piece  of  work  and  must  be  softened  before  it  can  be  removed, 

101 


102  ANNEALING,  HARDENING,  TEMPERING 

The  procedure  is  to  heat  the  steel  until  it  shows  a  dull  red 
when  held  in  a  dark  place,  then  plunge  it  in  water.  Soapy 
water  gives  very  good  results  for  this  purpose. 

Hardening. — If  instead  of  allowing  steel  to  cool  slowly 
from  a  cherry-red  heat  it  is  cooled  suddenly,  it  will  become 
very  hard.  The  hardness  will  depend  upon  the  percentage  of 
carbon  in  the  steel,  the  temperature  at  which  it  is  hardened, 
and  the  speed  with  which  it  is  cooled.  The  following  two 
laws  of  hardening  should  be  borne  in  mind  while  hardening 
tool  steel : 

1.  The  higher  the  percentage   of  carbon   in  the  steel  the 
lower  will  be  the  refining,  or  hardening,  heat. 

2.  The   more  quickly   steel  is   cooled    from   the   hardening 
heat  the  harder  it  becomes. 

From  these  laws  it  follows  that  the  hardness  of  any  piece 
of  steel  may  be  varied  by  varying  the  rate  of  cooling. 

Refining  Heat. — The  only  way  to  determine  the  proper 
heat  at  which  a  piece  of  tool  steel  should  be  hardened  is  by 
experimenting  in  the  following  manner :  Draw-out  a  sample 
of  the  steel  into  a  bar  about  y%  inch  square.  One  end  of  this 
bar  is  heated  to  a  dull  red  and  quickly  cooled  in  water  having 
a  temperature  of  about  70°  F.  When  cold  it  is  placed  on  the 
anvil  with  about  1  inch  of  this  end  projecting  over  the  rounded 
edge.  An  attempt  is  then  made  to  break  off  this  projecting 
end  by  hitting  it  with  a  hand-hammer.  If  it  bends,  the  tem- 
perature at  which  it  was  hardened  was  not  high  enough.  This 
test  should  then  be  repeated,  raising  the  temperature  slightly 
each  time  until  the  steel,  when  cooled,  will  be  file-hard,  i.  e.,  a 
file  will  not  cut  it ;  will  not  break  easily ;  and  will  have  a  fine 
grain.  If  the  temperature  is  raised  too  high  the  grain  of  the 
steel  will  be  coarse,  showing  large  crystals.  The  steel  will  also 


RECALESCENCE  103 

be  very  brittle,  not  so  strong,  and  will  not  hold  a  cutting  edge 
well. 

The  refining  heat  may  then  be  defined  as  the  temperature 
which  gives  the  steel,  when  hardened,  the  finest  grain,  leaves 
it  file-hard,  and  also  leaves  it  in.  the  strongest  condition. 

Recalescence. — When  steel  is  heated  to  a  bright-red  heat 
and  allowed  to  cool,  the  rate  of  cooling  is  not  uniform.  It  will 
cool  gradually  until  a  certain  temperature  is  reached,  when  it 
will  seem  to  become  hotter  for  a  short  time  and  the  color 
lighter.  Below  this  temperature  the  cooling  is  gradual  again. 

The  temperature  at  which  this  apparent  re-heating  occurs 
is  the  proper  refining  or  hardening  heat  for  the  steel  tested.  It 
can  be  determined  by  the  use  of  a  Pyrometer.  This  phenom- 
enon is  known  as  "recalescence."  In  water  annealing,  the  hard 
steel  should  be  heated  to  somewhat  below  this  temperature. 

Tempering. — After  tools  have  been  hardened  in  the  man- 
ner described  above,  they  are  too  hard  and  brittle  for  most 
purposes,  and  must  be  softened  a  little.  This  process  of 
slightly  softening  the  hardened  steel  is  known  as  "drawing 
the  temper,"  or,  properly,  "tempering." 

Tempering  is  accomplished  by  reheating  the  hardened 
steel,  and  quickly  cooling  it  again,  the  amount  of  the  reheat- 
ing depending  upon  the  use  for  which  the  tool  is  intended. 
The  accompanying  chart  gives  the  approximate  temperatures 
at  which  various  tools  are  tempered.  Thus  if  a  piece  of  hard- 
ened tool  steel  is  heated  to  a  temperature  of  about  430°  F.  it 
will  be  only  slightly  softened,  and  will  still  be  hard  enough  for 
small  lathe  tools. 

These  temperatures  can  be  determined  in  several  ways.  If 
the  hardening  and  tempering  is  done  on  a  large  scale,  an  oil 
bath  may  be  used.  Such  a  bath  is  maintained  at  the  desired 
temperature  as  indicated  by  a  thermometer,  and  the  steel 
placed  in  it  after  being  hardened.  When  the  steel  has  reached 


104 


ANNEALING,  HARDENING,  TEMPERING 


the  same  temperature  as  the  bath,  it  is  removed  and  quickly 
cooled. 

For  ordinary  purposes  the  temperature  is  gauged  by  the 

GUIDE    FOR    HARDENING   AND    TEMPERING 
CARBON    TOOL    STEEL 


APPLICATIONS. 

TEMPER- 
ATURE 

COLOR  OF 
OXIDE 

!  ACTION  OF  FILE 

Engraving  tools,  lathe  tools, 
and  tools  for  cutting  hard 
metals  at  slow  speed. 

430° 

Very  pale 
yellow 

File  will  hardly 
mark 

Lathe  and  planer  tools  for 
heavy  work,  milling  cut- 
ters, taps,  reamers,  thread- 
cutting  tools,  punches,  dies, 
etc. 

460° 

Straw  yellow 

File  will  mark 

Various  punches  and  dies, 
wood-working  tools,  twist 
drills,  sledges,  blacksmith's 
hand-hammers,  stone  drills, 
etc. 

.    500° 

Deep  straw 
(or 
arown-yellow) 

File  will  mark 
a  little  deeper 

Shear  knives,  rivet  snaps, 
punches,  boilermakers' 
tools,  and  cold  chisels  for 
light  work. 

525° 

Light  purple 

Cold  chisels  for  ordinary 
work,  gears,  surgical  in- 
struments, etc. 

570° 

Blue  tinged 
with  red 

Files,  but  with 
difficulty 

Springs,  picks,  etc. 

580° 

Blue 

625°  to  650° 

Gray  or  green 

TEMPERING  105 

color  of  oxide  on  the  steel.  This  film  of  oxide  forms  on  the 
polished  surface  of  steel  if  heat  is  applied.  It  is  first  visible 
at  a  temperature  of  about  430°,  when  the  color  is  a  very  pale 
yellow.  As  the  temperature  rises,  the  color  changes  from 
pale  yellow  to  dark  yellow,  to  brown,  then  to  light  purple,  to 
dark  purple,  and  finally  to  blue.  These  colors  serve  as  a  guide 
for  tempering.  After  the  metal  has  been  cooled  they  remain 
visible,  inHicating  the  last  temperature  to  which  it  was  heated. 
Common  iron  shows  this  same  phenomenon. 

Up  to  a  visible  red  heat,  the  higher  the  temperature  of  re- 
heating the  softer  the  steel  becomes.  If  the  steel  is  reheated 
to  too  high  a  temperature  it  must  be  rehardened  and  tempered 
again. 

The  best  shop  method  for  testing  the  hardness  of  a  tool  is 
to  try  it  with  a  file.  The  action  of  a  file  on  steel  which  has 
oeen  tempered  at  the  different  colors  is  given  in  the  chart; 
but  while  this  method  may  indicate  that  a  tool  has  the  proper 
hardness,  the  grain  may  be  coarse  because  of  too  high  a  hard- 
ening heat.  This  last  condition  gives  the  tool  a  crumbly  and 
scratchy  cutting  edge. 

Tempering  Only  the  Cutting  Edges  of  Tools. — Certain 
tools  are  tempered  only  at  the  cutting  edges,  the  main  body 
being  left  unhardened  in  order  to  resist  shocks.  They  are  all 
tempered  in  the  same  manner,  the  only  difference  being  in  the 
final  hardness  of  the  cutting  edge.  The  tempering  of  a  chisel 
will  serve  as  an  example  of  the  process  employed. 

After  the  chisel  has  been  forged,  it  should  be  allowed  to 
cool  until  black,  and  then  reheated  for  hardening  about  3 
inches  back  from  the  edge.  When  reheating,  the  cutting  edge 
should  be  kept  high  in  the  fire,  so  tnat  the  heat  will  be  applied 
to  the  thick  part  of  the  chisel  and  flow  toward  the  cutting 
edge.  The  chisel  should  be  kept  well  covered  with  coke,  and 
heated  slowly. 

The  hardening  is  done  by  quick  cooling  in  water  at  a  tern- 


106 


ANNEALING,  HARDENING,  TEMPERING 


perature  of  about  70°  F.  This  water  should  be  clean,  since 
dirty  water  retards  cooling.  The  chisel  is  held  vertically,  and 
the  cutting  edge  gradually  inserted  in  the  water  until  about 
half  of  the  heated  portion  is  below  the  surface.  The  tool  must 
be  moved  around  while  doing  this,  so  that  the  steam  generated 
will  not  blow  the  water  away  and  retard  the  cooling.  It 
should  never  be  held  stationary  in  the  water,  since  if  there  is 
a  well-defined  line  between  the  cooled  and  hot  portions  the 
chisel  will  probably  break  at  that  point.  The  chisel  is  then 
quickly  plunged  into  the  water  and  immediately  removed,  con- 
siderable heat  remaining  in  it  but  the  edge  being  cold. 


Pale  Yellow 
Straw  Yellow 
Deep  Straw 
Light   Purple 
Blue  ringed  with  Red 


n 


Fig  A7. 


For  the  purpose  of  watching  the  colors,  the  cutting  end  is 
polished  with  a  carborundum  stone  or  a  piece  of  emery  cloth. 
These  temper  colors  will  first  appear  next  to  the  heated  por- 
tion of  the  chisel  when  the  heat  from  that  part  runs  down  into 
the  point.  They  will  move  down  toward  the  point  in  the  order 
shown  at  A  in  Fig.  47.  When  the  color  at  the  cutting  edge  is 
blue  tinged  with  red,  as  at  B,  the  tool  is  completely  cooled  to 
prevent  further  reheating  and  softening  of  the  point. 

A  lathe  tool  is  hardened  and  tempered  in  the  same  man- 
ner, except  that  the  final  cooling  is  done  when  the  yellow 
scale  appears  at  the  cutting  edge. 


TEMPERING  107 

Hardening  and  Tempering  Tools  Thruout. — When  a  tool 
is  to  be  tempered  thruout  it  is  first  heated  uniformly  to  the  re- 
fining heat,  and  then  completely  cooled.  After  removing  it 
from  the  cooling  bath  it  is  dried,  and  the  surface  polished.  It 
is  tempered  by  laying  it  on  a  piece  of  red-hot  iron  until  the 
desired  color  appears  on  the  polished  surface,  when  it  is  again 
cooled  in  water  or  oil.  The  tool  should  be  turned  frequently 
in  order  to  have  the  heating  take  place  uniformly.  If  this  is 
not  done  the  parts  in  contact  with  the  hot  iron  will  become 
overheated  and  too  soft  before  the  other  parts  are  hot  enough 
to  show  the  desired  colors.  The  reheating  is  sometimes  done 
over  the  fire,  or  on  a  plate  laid  over  the  fire. 

Methods  of  Cooling. — The  degree  of  hardness  in  a  piece 
of  carbon  steel  depends  upon  the  rapidity  of  its  cooling  from 
the  refining  heat.  Some  tools,  such  as  dies,  files,  etc.,  which 
must  be  extremely  hard,  are  hardened  by  plunging  them,  when 
at  the  refining  heat,  into  a  bath  of  cold  brine.  The  latter  cools 
the  steel  faster  than  water,  and  leaves  it  much  harder.  Tools 
and  articles  such  as  springs,  which  require  toughness  rather 
than  hardness,  are  cooled  in  oil.  The  oil  does  not  cool  them 
as  rapidly  as  water. 

Care  should  be  taken  not  to  remove  the  tools  from  the 
bath,  when  being  hardened  thruout,  until  they  have  completely 
cooled,  as  they  are  likely  to  crack. 

Forging  Heat  of  Tool  Steel. — The  temperature  at  which 
tool  steel  should  be  worked  depends  on  the  amount  of  forging 
and  hammering  to  be  done.  If  a  large  amount  of  hammering 
is  necessary  for  shaping  a  piece,  it  should  be  worked  at  a  yel- 
low heat.  At  this  heat  the  steel  is  plastic  and  works  easily. 
Much  heavy  hammering  is  good  for  the  steel,  since  it  refines 
the  grain.  When  the  forging  or  tool  is  merely  to  be  smoothed 
or  finished,  the  work  should  be  done  at  a  temperature  just 
above  the  refining  heat. 

Heating  Steel  for  Hardening. — The  fire  used  for  heating 


108  ANNEALING.  HARDENING,  TEMPERING 

tool  steel  should  have  a  good  bed,  or  bottom,  of  hot  coke,  in 
order  to  heat  the  cold  air  coming  thru  the  tuyere  iron.  If  the 
air  is  not  warmed  very  much  and  a  piece  in  the  fire  is  turned 
over  occasionally,  the  heated  portions  of  the  piece  will  be 
cooled.  This  cooling  will  make  it  contract  and  tend  to  crack 
it.  The  piece  should  also  be  kept  well  covered  with  hot  coke, 
in  order  that  the  oxygen  in  the  air  will  not  attack  and  decar- 
bonize it. 

Carbon  steel  should  be  heated  slowly  enough  to  obtain  a 
uniform  color  on  it.  If  it  is  heated  too  rapidly  the  corners 
and  edges  will  become  overheated  before  the  main  body  of 
the  piece  has  reached  the  proper  temperature.  Allowing  these 
parts  to  cool  to  the  proper  temperature  will  not  do  much  good, 
as  the  grain  in  them  will  be  coarse  and  there  will  be  internal 
stresses  set  up. 

Importance  of  Uniform  Heating. — If  one  part  of  a  tool 
to  be  hardened  is  heated  more  than  another  there  will  be 
an  unequal  expansion.  The  contraction  which  takes  place  when 
the  tool  is  cooled  will  also  be  unequal.  This  causes  internal 
stresses  in  the  tool,  which  may  crack  it  at  any  time.  For  this 
reason  pieces  of  tool  steel  sometimes  break  with  a  loud  report 
after  being  hardened. 

Hardening  at  a  Rising  Heat. — A  piece  of  carbon  steel 
should  never  be  allowed  to  "soak"  in  the  fire  after  having  been 
uniformly  heated  to  the  desired  temperature.  This  causes  it 
to  become  decarbonized,  coarse  in  grain,  and  brittle.  It  should 
be  removed  from  the  fire  and  hardened  just  as  soon  as  the  de- 
sired temperature  has  been  reached. 

Restoring  the  Grain. — In  case  the  grain  of  a  piece  of  steel 
has  become  coarse  thru  overheating,  it  may  and  should  be  re- 
fined in  one  of  the  following  ways: 

1.  By  reducing  the  size  of  the  material  with  a  trip-ham- 
mer or  sledge,  thereby  closing  the  grain. 

2.  By  allowing  the  steel  to  cool  and  then  reheating  it  to 
the  refining  heat. 


COOLING  109 

Restoring  the  grain  by  reheating  may  not  make  the  steei 
quite  as  good  as  it  was  before  being  overheated.  Unless  it 
has  been  overheated  for  some  time  or  actually  burned,  ham- 
mering will  practically  restore  it  to  its  original  quality. 

Caution. — If  the  refining  heat  of  a  piece  of  steel  is  1400° 
F,  and  thru  carelessness  the  piece  is  heated  to  1600°,  it  should 
not  be  cooled  in  the  air  to  1400°  and  then  hardened.  This 
would  give  it  the  hardness  of  the  1400°  temperature  together 
with  the  coarse  grain  due  to  overheating.  The  grain  of  tool 
steel  remains  in  the  condition  caused  by  the  highest  tempera- 
ture to  which  it  has  been  heated  until  it  is  cooled  and  reheated. 
It  then  adjusts  itself  to  the  new  temperature. 

Warping  in  Cooling. — When  heated  steel  is  cooled  it  con- 
tracts, and  unless  the  contraction  is  uniform  it  is  liable  to  be 
warped  or  bent  out  of  shape.  To  avoid  this  warping  as  much 
as  possible  the  piece  must  first  be  heated  uniformly,  and  then 
cooled  uniformly  by  dipping  it  in  the  cooling  bath  in  the  proper 
manner. 

If,  for  instance,  a  carving  knife  were  uniformly  heated  and 
dipped  into  oil  or  water  so  that  one  of  the  flat  sides  struck 
the  bath  first,  that  side  would  be  cooled  more  quickly  than 
the  other  and  the  blade  would  be  badly  warped.  By  dipping 
it  in  edge-wise  both  sides  would  be  cooled  .at  the  same  rate, 
and  the  warping  would  be  very  slight. 

Cylindrical  pieces  are  generally  inserted  end  first  in  the 
cooling  bath;  while  square,  flat  pieces,  carving  knives,  shear 
blades,  and  articles  of  similar  character,  are  dipped  edge-wise. 

Hardening  Thin,  Flat  Articles. — Very  thin,  flat  pieces  of 
steel  are  sometimes  hardened  by  heating  them  uniformly  to 
the  refining  heat  and  placing  them  between  heavy  plates  of 
iron  whose  faces  are  smeared  with  oil.  The  insertion  of  the 
steel  between  the  plates  must  be  done  as  quickly  as  possible. 
This  method  leaves  the  steel  hard,  true,  and  flat. 

Tempering  Taps. — When  hardening  tools  having  teeth  or 


110  ANNEALING,  HARDENING,  TEMPERING 

projections,  such  as  taps  and  reamers,  they  should  not  be 
heated  more  than  is  absolutely  necessary.  The  heating  should 
be  done  in  a  muffle  furnace,  but  in  case  this  is  not  available  it 
can  be  done  over  the  forge  fire  by  enclosing  the  tap  in  a  piece 
of  pipe,  to  prevent  the  teeth  from  coming  in  direct  contact 
with  the  fire.  In  the  latter  method  the  pipe  in  which  the  heat- 
ing is  done  should  be  longer  and  at  least  2  inches  larger  in 
diameter  than  the  tool.  The  tap  must  be  heated  slowly  and 
revolved  frequently,  in  order  to  obtain  a  uniform  heat. 

After  the  refining  heat  has  been  reached  the  tap  is  cooled 
in  tepid  water.  It  is  plunged  end  first  and  then  moved  up, 
down,  and  around  in  the  water,  to  cool  it  thoroly  and  to 
prevent  the  steam  generated  from  retarding  the  cooling. 


Fig.  48. 

When  the  tap  has  been  completely  cooled  it  is  taken  out  and 
polished  with  a  special  emery  wheel,  or  with  emery  cloth,  in 
order  that  the  temper  colors  may  be  readily  seen. 

It  is  tempered  by  inserting  in  a  heated  collar,  as  shown  in 
Fig.  48.  It  should  be  constantly  revolved  while  inside  the  col- 
lar, and  moved  back  and  forth  thru  it,  depending  on  how  the 
colors  are  appearing.  In  no  case  should  the  teeth  come  in 
contact  with  the  inside  of  the  collar.  When  the  desired  color, 
deep  straw  or  brown,  has  appeared,  the  tap  is  cooled  in  oil. 

Tempering  Carving  Knives. — When  hardening  carving 
knives  on  a  small  scale  they  are  generally  heated  in  the  same 
manner  as  a  tap,  i.  e.,  inside  of  a  piece  of  pipe.  The  pipe 
should,  however,  be  first  heated  uniformly  by  revolving  it 
slowly  in  the  fire.  The  knife  is  then  held  inside  of  it,  and  very 


TEMPERING  SHEAR  BLADES  111 

little,  blast  turned  on.  The  heating  should  be  done  slowly,  in 
order  to  avoid  warping  or  bending.  When  heated  uniformly 
to  the  refining  heat,  the  blade  is  cooled  in  fish  oil,  dipping  it 
edge- wise  with  the  back  of  the  knife  down.  If  the  blade  be- 
comes bent  before  hardening,  no  attempt  should  be  made  to 
straighten  it  below  a  red-heat,  otherwise  it  will  warp  again 
when  being  cooled. 

After  the  knife  has  been  hardened  it  is  polished  on  an 
emery  buffer  and  held  in  the  flame  of  the  fire  to  temper  it. 
The  final  cooling  is  done  in  oil,  when  the  color  of  the  scale  is 
blue  tinged  with  red. 

Tempering  Shear  Blades. — In  small  shops  shear  blades 
are  hardened  in  the  following  manner :  Two  wrought-iron 
plates  the  same  length  as  the  blade,  1  inch  narrower,  and  $/% 
inch  thick  are  placed  on  either  side  of  the  blade,  so  that  about 
1  inch  of  the  cutting  edge  is  exposed  for  its  entire  length. 
Holes  corresponding  to  those  in  the  blade  are  drilled  in  the 
plates,  and  the  three  pieces  are  bolted  together.  They  are 
then  placed  in  a  furnace,  heated  to  the  refining  heat,  and  cooled 
in  tepid  water. 

When  the  blade  is  cold  the  plates  are  removed,  and  one 
side  of  the  blade  polished,  in  order  to  watch  the  temper  colors. 
The  blade  is  tempered  by  standing  it  on  edge  lengthwise  on  a 
piece  of  hot  iron.  As  soon  as  the  desired  color,  a  straw  yel- 
low, reaches  the  cutting  edge,  the  blade  is  cooled  in  fish  oil. 

These  plates  prevent  the  body  of  the  blade  from  becoming 
as  hot  as  the  cutting  edge,  and  cause  it  to  cool  slowly.  This 
makes  the  body  tough  for  resisting  shocks.  The  plates  also 
keep  the  blade  from  warping  when  cooling. 

Tempering  Springs. — When  pieces  of  steel  must  be  tough- 
ened so  that  they  will  return  to  their  original  form  when  bent 
or  twisted,  they  are  generally  "spring  tempered."  This  is  the 
same  as  ordinary  tempering,  except  that  more  of  the  hardness 
is  removed,  making  the  steel  tougher. 


112  ANNEALING,  HARDENING,  TEMPERING 

Fish  or  animal  oil  is  generally  used  for  cooling  in  spring 
tempering.  It  gives  better  control  over  the  hardness,  because 
the  steel  is  not  cooled  quite  so  fast  as  in  water.  The  latter 
can  be  used,  but  it  makes  it  harder  to  properly  gauge  the 
tempering. 

For  many  purposes  a  grade  of  steel  made  especially  for 
springs  gives  better  results  than  regular  tool  steel.  It  is  there- 
fore a  good  policy  to  state  the  requirements  of  a  spring  when 
ordering  material  for  it. 

Tempering  springs  on  a  small  scale  is  generally  done  by 
the  blazing  off  or  flashing  process.  The  spring  is  first  hard- 
ened in  the  fish  oil  and  then  re-heated,  while  still  wet  with  oil, 
in  the  flame  of  the  fire.  When  the  oil  on  it  blazes  up,  it  is 
plunged  for  an  instant  into  the  oil  bath.  This  procedure  is 
continued  until  the  oil  blazes  uniformly  over  the  entire  spring 
at  the  same  time,  which  is  generally  after  about  three  plunges 
in  the  bath.  It  is  then  again  completely  cooled  in  the  oil. 
Springs  are  seldom  uniform  in  thickness,  hence  the  thin  parts 
heat  more  quickly  than  the  others.  The  momentary  plunge 
into  the  oil  bath  cools  these  thin  parts  somewhat  without  af- 
fecting the  rest  of  the  spring  very  much.  In  this  way  the 
entire  spring  is  brought  to  the  flash-point  temperature  of  the 
oil,  which  is  about  600°  F. 

When  large  numbers  of  springs  are  to  be  handled,  an  oil 
bath  kept  at  the  proper  temperature  is  often  provided  for  tem- 
pering. The  springs  are  placed  in  this  bath  after  being  hard- 
ened, and  are  allowed  to  remain  there  for  a  certain  length  of 
time,  depending  upon  their  size.  They  are  then  removed  and 
cooled  in  oil. 

Case-Hardening. — On  account  of  the  small  amount  of  car- 
bon in  wrought  iron  and  soft  steel,  they  cannot  be  hardened 
to  any  appreciable  extent.  If,  however,  they  are  heated  to  a 
high  temperature  while  in  contact  with  some  substance  con- 
taining carbon,  such  as  ground  bone,  charcoal,  or  charred 


CASE-HARDENING  113 

leather,  their  outside  surfaces  will  absorb  some  of  the  carbon. 
This  gives  these  surfaces  the  characteristic  properties  of  tool 
steel,  so  that  they  can  be  hardened  and  tempered  in  the  same 
manner.  The  process  of  treating  the  iron  or  steel  so  as  to 
make  the  outside  surface  hard  is  known  as  case-hardening. 

A  piece  of  material  which  has  been  case-hardened  con- 
sists of  a  wrought-iron  or  machine-steel  core  with  a  tool- 
steel  surface.  Machine  steel  is  used  ordinarily  for  case- 
hardening.  Steel  treated  in  this  way  is  particularly  valuable 
for  bicycle  parts,  since  it  will  not  bend  easily,  resists  shocks 
by  reason  of  its  soft  core,  and  is  much  cheaper  than  tool  steel. 
The  depth  to  which  the  material  is  carbonized,  or  the  pene- 
tration of  the  carbon,  depends  upon  the  temperature  to  which 
the  material  is  heated  while  in  contact  with  the  carbonizer,  the 
length  of  time  it  is  maintained  at  that  temperature,  and  the 
carbonizing  substance  used. 

There  are  three  practical  shop  methods  which  are  used  for 
case-hardening. 

FIRST  METHOD. — Small  pieces  and  pieces  which  require 
only  a  very  thin  shell  of  hard  steel  are  first  heated  to  a  high 
red  heat,  then  removed  from  the  fire  and  sprinkled  with  cyan- 
ide of  potassium.  The  latter  must  be  reasonably  pure  in  order 
to  obtain  the  best  results.  The  pieces  are  reheated  for  a  few 
seconds,  to  allow  the  carbon  from  the  cyanide  time  to  soak  in, 
and  are  then  quickly  cooled  in  water.  This  method  is  also  used 
when  only  the  surface  of  a  hole  or  a  small  part  of  a  piece  is 
to  be  hardened. 

By  taking  a  handful  of  sharp  sand  and  scouring  the  piece 
under  water  while  it  is  still  hot,  all  of  the  dirt  and  scale  may 
be  removed. 

SECOND  METHOD. — It  is  often  desired  to  give  the  surface 
of  a  tool  a  mottled  effect  when  case-hardening  it.  This  can 
be  done  in  the  following  manner : 

The  tool  is  first  polished  and  then  placed  in  a  cast  iron  pot 


114  ANNEALING,  HARDENING,  TEMPERING 

containing  molten  cyanide  of  potassium.  This  pot  is  kept  on 
the  fire  until  after  the  tool  is  removed.  The  tool  is  allowed 
to  remain  in  the  cyanide  until  the  desired  absorption  of  car- 
bon has  been  reached.  Ten  minutes  is  required  for  a  pene- 
tration of  about  .001  inch.  It  is  then  removed  with  a  pair  of 
tongs  and  dropped  thru  a  distance  of  5  or  6  feet  into  cold 
water. 

The  same  effect  can  be  obtained  by  passing  the  piece  thru 
a  spray  of  water  after  its  removal  from  the  cyanide  pot,  and 
then  cooling  it.  Wherever  a  fine  spray  strikes  the  piece  a 
vine-like  effect  is  produced. 

Caution. — Do  not  dip  wet  tongs  into  molten  cyanide,  as  this 
will  cause  the  cyanide  to  spatter  around.  Cyanide  crystals  are 
deadly  poison.  Care  should  also  be  taken  to  avoid  the  fumes 
from  the  cyanide  as  much  as  possible,  for  they  are  very  pois- 
onous. 

THIRD  METHOD.   Pack  Hardening. — In  most  commercial 
practice  case-hardening  is  done  in  the  following  manner: 

The  carbonizer,  which  may  be  ground  bone,  charcoal,  or 
charred  leather,  is  dried  well  and  reduced  to  a  fine  powder. 
A  layer  of  it  about  \l/2  inches  thick  is  placed  on  the  bottom 
of  a  hardening  pot,  and  on  top  of  it  a  layer  of  the  articles  to 
be  hardened.  These  must  not  touch  each  other.  Another 
layer  of  carbonizer  is  added,  and  on  top  of  it  another  layer  of 
the  pieces.  This  building-up  process  is  continued  until  the 
pot  is  full,  when  a  final  covering  of  carbonizer  is  added.  A  lid 
is  put  on,  and  all  joints  are  closed  with  clay  to  prevent  oxida- 
tion. The  pot  is  then  placed  in  a  furnace  and  heated  to  a  tem- 
perature of  about  1800°  F,  a  full  orange  heat. 

When  the  carbonizing  action  has  continued  long  enough, 
about  six  hours  being  required  for  a  penetration  of  about  tV 
inch,  the  pot  is  removed  from  the  furnace  and  allowed  to  cool 
slowly.  It  is  then  opened,  and  the  articles  cleaned  with  a 
brush.  They  are  reheated  to  a  temperature  of  about  1450°, 


HIGH-SPEED  STEEL  115 

and  quickly  cooled  in  cold  water  or  oil.  This  reheating  re- 
fines the  grain,  making  the  final  product  tough  and  strong. 

Hardening  pots  are  made  out  of  either  cast  iron  or  wrought 
iron.  The  latter  stand  the  heat  better  and  last  longer,  but  are 
more  expensive. 

This  process  is  sometimes  employed  to  enrich  the  surface 
of  low-grade  tool  steel.  The  tool  steel  is  packed  with  a  car- 
bonizing material  in  iron  boxes,  and  heated  in  a  furnace.  The 
contents  of  the  box  are  kept  at  a  temperature  of  about  1475°  F. 
for  about  two  hours,  depending  upon  the  depth  of  carbonizing 
required.  After  removing  the  box  from  the  furnace  the  pieces 
are  withdrawn,  and  cooled  in  oil. 

TREATMENT  OF  HIGH-SPEED  STEEL.* 

High-speed  steel  generally  requires  different  treatment  from 
high-carbon  steel,  on  account  of  the  peculiarities  of  some  of 
its  constituents.  The  same  general  method  is  usually  followed, 
but  slight  modifications  are  sometimes  required  to  obtain  the 
best  results.  For  this  reason  it  is  advisable  to  follow  the 
special  directions  given  by  the  manufacturer. 

Cutting  Stock. — High-speed  steel  should  be  heated  for 

cutting,  since  breaking  it  cold  has  a  tendency  to  produce 
cracks.  Small  stock  is  often  cut  by  grinding  a  groove  around 
it  with  an  emery  wheel  and  then  breaking  it. 

Forging  Heat. — The  proper  temperature  for  forging  this 
steel  is  about  1800°  F.,  a  yellow  heat.  It  should  be  heated 
slowly  until  it  becomes  red  hot,  and  may  then  be  heated  faster 
up  to  a  yellow  heat.  If  heated  too  quickly  the  outside  of  the 
steel  may  become  hot  while  the  center  is  still  comparatively 
cold.  Hammering  it  in  this  condition  is  liable  to  cause  inter- 
nal cracks. 


*  For  further  information  on  the  treatment  of  high-speed  steel  the 
student  is  referred  to  "On  the  Art  of  Cutting  Metals,"  by  Mr.  F.  W. 
Taylor. 


116  ANNEALING,  HARDENING,  TEMPERING 

The  Fire  used  for  heating  high-speed  steel  should  not  be 
a  freshly-made  one.  It  should  have  burned  for  some  time,  in 
order  to  produce  the  intense  heat  necessary  for  proper  hard- 
ening. There  should  be  a  good  ,bed  of  hot  coke  around  the 
steel,  to  bring  it  to  the  hardening  heat  quickly. 

Heating  for  Hardening. — In  heating  the  end  of  a  high- 
speed steel  tool  for  hardening  it  should  be  brought  slowly  to  a 
full  red  heat,  and  then  quickly  heated  to  the  melting  point. 
While  doing  this  the  tool  should  be  turned  frequently,  to  in- 
sure a  uniform  high  heat  thruout  the  entire  end.  At  this  tem- 
perature the  nose  of  the  tool  sweats  or  becomes  wet.  The 
higher  the  temperature  to  which  the  tool  is  heated  for  harden- 
ing the  greater  will  be  its  property  of  red  hardness,  or  the 
higher  the  temperature  at  which  it  will  still  hold  its  cutting 
edge. 

Care  should  be  taken  when  removing  the  tool  from  the  fire 
to  see  that  the  point  does  not  hit  the  coke.  At  this  high  tem- 
perature the  steel  is  soft  and  crumbly,  and  will  break  easily. 
If  the  tool  becomes  pitted,  or  if  some  of  the  corners  fall  off 
due  to  the  excessive  heat,  it  will  still  be  in  good  condition  after 
grinding  off  the  irregularities. 

Cooling. — The  tool  is  cooled  from  this  high  heat  by  any 
one  of  several  methods.  Its  nose  may  be  quickly  cooled  by  the 
air-blast  from  an  air  compressor  or  power  fan.  Another  way 
is  to  simply  immerse  it  in  oil.  Cooling  it  in  water  tends  to 
crack  it,  but  tools  are  sometimes  partially  cooled  in  water  and 
then  finally  cooled  in  oil.  The  latter  method  makes  the  tool 
somewhat  harder  than  either  air  or  oil  cooling. 

Lead  Heat  Treatment. — Still  another  method  is  to  plunge 
the  highly  heated  tool  into  a  vat  of  molten  lead  at  a  tempera- 
ture of  about  1500°  F.  It  is  allowed  to  remain  there  for  a 
time,  depending  on  the  size  of  the  tool  (ten  minutes  for  an 
ordinary  lathe  tool),  and  is  then  transferred  to  another  vat 


ANNEALING  117 

at  a  lower  temperature.    This  method  is  not  suitable  for  small 
shops,  as  it  is  more  expensive  than  the  air-blast  or  oil  method. 

Annealing. — High-speed  steel  sometimes  becomes  refrac- 
tory when  dressing  it,  so  that  it  crumbles.  In  such  cases  it 
should  be  annealed.  This  may  be  done  in  the  same  manner 
that  carbon  tool  steel  is  treated. 


CHAPTER  VII. 
TOOL  FORGING. 

Selection  of  Steel  for  Tools. — There  are  so  many  grades 
of  tool  steel  on  the  market  that  it  is  very  hard  to  select  the 
best  material  for  a  tool  without  knowing  somewhat  of  the 
characeristics  of  each  grade.  This  information  is  generally 
given  in  the  catalogues  of  the  manufacturers,  which  should 
be  consulted  before  ordering  the  material.  One  of  the  best 
ways  is  to  order  the  steel  for  a  stated  purpose,  without  speci- 
fying any  particular  brand,  thus  putting  the  responsibility  of 
selecting  the  right  kind  on  the  manufacturer  or  his  agent. 

Steel  is  sometimes  designated  by  the  number  of  .01%'s  of 
carbon  that  it  contains.  If  there  is  1%  of  carbon  in  it,  it  is 
known  as  100  point  carbon  steel.  Fifty  carbon,  or  fifty-point 
carbon,  indicates  a  steel  containing  .5%  of  carbon. 

In  order  to  provide  a  rough  guide  for  the  student  and  to 
illustrate  the  fact  that  different  tools  require  different  grades 
of  steel,  the  following  table  is  given: 
%  CARBON  USED  FOR 

.70  to  .80  Blacksmiths'  tools,  such  as  rivet-sets,  sledges,  hand- 
hammers,  fullers,  flatters,  etc.;  wedges,  pick-points, 
and  other  tools  that  are  welded. 

.80  to     .90        Shear  blades,  caulking  tools,  punches  for  boilermakers, 

axes,  rock  drills,  hand  chisels,  and  drop-forging  dies. 

.90  to  1.00        Mining   and    rock    drills,    chisels,    dies,    shear    blades, 

knives,  and  axes. 

1.00  to  1.10        Lathe   centers;    small   hand   tools;    knives,   axes,  and 
flat   drills. 

1.10  to  1.20        Lathe  and  planer  tools,  twist  drills,  reamers,  milling 
cutters,  granite  cutters'  tools,  lathe  centers. 

1.20  to  1.30        Wood-  and  metal-turning  tools,  graving  tools,  etc. 
1.30  to  1.40        Tools   for  turning  chilled  and  hard  metals;  finishing 
tools,  and  cutters. 

118 


COLD  CHISEL  119 

Before  attempting  to  forge  and  harden  his  first  tool  a  stu- 
dent should  experiment  with  a  sample  of  the  tool  steel,  in  order 
to  determine  its  refining  heat  and  to  learn  how  to  restore  the 
grain  if  it  is  overheated.  He  should  also  practice  drawing  the 
colors  on  pieces  of  scrap  machine  steel. 

Tool-steel  stock  should  be  cut  while  hot.  If  it  is  cut  cold 
cracks  are  likely  to  be  formed,  which  will  appear  when  the 
tool  is  hardened. 


Project  26.    Cold  Chisel.    (Plate  XXIX.) 

STEP  ONE. — Heat  the  head  end  to  a  yellow  heat,  and  taper 
it  as  shown  at  1. 

STEP  Two. — Forge  the  other  end  to  the  form  shown  at  2 
at  a  yellow  heat.  About  %  mch  of  this  end  should  extend 
over  the  sharp  edge  of  the  anvil,  and  the  tapering  should,  be 
continued  up  to  that  edge.  The  finishing  may  be  done  with 
a  flatter  at  a  temperature  just  above  the  refining  heat.  If  it  is 
hammered  out  with  heavy  blows  when  black,  the  grain  will  be 
crushed. 

STEP  THREE. — The  extreme  end,  A,  may  be  cut  off  with 
the  hardie,  or  it  may  be  cut  partly  thru  and  broken  after  the 
chisel  has  been  hardened  and  tempered.  The  latter  method 
exposes  the  grain  and  indicates  whether  the  heat  was  correct. 
If  the  edge  of  the  tool  is  too  thin  when  cut  it  should  not  be  up- 
set, as  this  makes  it  likely  to  crack.  It  must  be  cut  off  shorter. 
The  chisel  should  be  allowed  to  cool  slowly,  in  order  to  re- 
move any  internal  stresses  that  may  have  been  caused  by  im- 
proper hammering. 

The  cutting  edge  is  tempered  to  a  blue-tinged-with-red 
color,  in  the  manner  already  described  in  the  previous  chapter. 
The  tip  is  then  ground  on  an  emery  wheel  to  an  angle  of  60°, 
as  shown. 


Projects  26  and  27. 


Plate  XXIX. 


COLD  CHISEL.  ^^  gf  Ocragona,  too|  slee| 


CAPE  CHISEL 


Stock-£x  64" Octagonal  tool  steel. 


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120 


CAPE  CHISEL  121 

Test  the  chisel  by  chipping  a  piece  of  cast  iron.  If  the  cut- 
ting edge  is  too  soft  it  should  be  rehardened  at  a  higher  tem- 
perature ;  while  if  it  breaks,  showing  a  coarse  grain,  it  should 
be  rehardened  at  a  lower  temperature. 

Project  27.    Cape  Chisel.    (Plate  XXIX.) 

The  cape  chisel,  Fig.  49,  is  used  for  cutting  grooves  and 
for  working  at  the  bottom  of  narrow  channels.  The  cutting 
edge,  A,  should  be  wider  than  the  rest  of  the  blade.  The 
taper  should  extend  to  B.  This  permits  the  blade  to  "clear" 


B 

Fig.  49.    CAPE  CHISEL.  . 

the  sides  of  a  groove,  or  slot,  when  the  groove  is  being  cut  to. 
the  width  of  the  edge  A. 

STEP  ONE. — Cut  the  stock  to  length,  and  taper  the  head 
end. 

STEP  Two. — The  other  end  is  brought  to  a  yellow  heat, 
and  tapered  square,  as  shown  at  2. 

STEP  THREE. — Make  the  fuller  marks  shown  with  y2-  or 
24-inch  top-  and  bottom-fullers.  These  marks  should  not  be 
made  too  deep,  or  the  blade  will  not  be  thick  enough.  Their 
object  is  to  prevent  the  blade  from  being  made  too  long. 

STEP  FOUR. — Place  the  end  over  the  large  part  of  the  horn 
and  flatten  it  with  a  hand-hammer -in  the  manner  shown  at 
A  in  Fig.  50.  Since  the  horn  acts  as  a  fuller,  this  stretches 
the  stock  lengthwise  and  enables  one  to  make  the  end  of  the 
blade,  A,  in  Fig.  49,  wider  than  the  section  at  B  without  mak- 
ing the  nicks  or  sharp  corners  which  would  be  formed  if  the 
edge  of  the  anvil  were  used. 

Extend  the  end,  M,  shown  at  B  in  Fig.  50,  over  the  sharp 


122 


TOOL  FORGING 


edge  of  the  anvil,  and  finish  the  blade  by  turning  it  on  edge 
and  hammering  it  to  a  point.  Smoothing  may  be  done  with 
a  set-hammer  and  a  flatter,  as  shown  at  C  and  D  in  Fig.  50. 


Fig.  50. 

Harden  and  temper  the  cutting  edge  in  the  same  manner  as 
the  flat  chisel.  . 

Project  28.    Round-Nose  Cape  Chisel.    (Plate  XXX.) 

The  round-nose  cape  chisel  is  used  for  cutting  oil  grooves 
and  for  centering  drills.  In  the  latter  capacity  it  is  known  as 
a  centering  chisel. 

This  chisel  is  made  in  the  same  manner  as  the  cape  chisel 
except  that  one  edge  of  the  blade  is  rounded,  as  shown  at  5. 
This  is  done  by  placing  the  blade  on  a  bottom-swage  and  using 
a  hand-hammer  or  a  flatter  on  the  top  edge. 


CENTER  PUNCH  123 

Project  29.    Center-Punch.     (Plate  XXX.) 

The  center-punch  is  so  simple  to  make  that  no  detailed  de- 
scription of  the  steps  required  is  necessary.  It  is  hardened  in 
the  same  manner  as  the  cold  chisel,  but  is  tempered  to  a  brown 
or  purple  color.  When  tempered,  the  center-punch  should 
mark  tool  steel  without  having  its  point  dulled. 

Lathe  Tools. — In  most  machine-shop  work  high-speed 
steel  tools  are  employed  in  preference  to  carbon  tools,  because 
they  can  be  used  for  faster  cutting  and  are  more  economical. 
For  light  lathe  work,  high-speed  steel  may  be  obtained  in  small 
pieces  already  hardened.  Where  a  fine  finish  is  desired  and 
the  cuts  are  light,  carbon  steel  tools  are  used.  They  will  take 
a  keener  edge  than  high-speed  steel,  but  the  cutting  must  be 
done  more  slowly.  The  following  five'  projects  give  the 
method  of  forming  and  tempering  some  of  the  common  forms 
of  high-carbon  lathe  tools. 

Project  30.    Round-Nose  Tool.    (Plate  XXXI.) 

STEP  ONE. — Forge  one  end  of  the  stock  from  three  sides 
to  a  blunt  point,  as  shown  at  1. 

STEP  Two. — Hammer  out  this  end  so  that  the  top  edge  is 
thicker  than  the  lower  one  and  has  clearance  all  around,  as 
shown  at  2.  This  is  done  because  all  the  cutting  done  by  this 


Fig.  51. 


Projects  28  and  29. 


Plate  XXX. 


ROUND  NOSE  CAPE  CHISEL. 


5tock-ix  6i"  Octagonal  Tool  steel. 


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124 


TOOL  FORGING  125 

tool  occurs  at  or  near  the  tip.     Trim  off  the  end  with  a  hot 
chisel,  and  bend  it  up  slightly,  as  shown. 

The  hardening  is  done  in  the  same  manner  as  with  the  cold 
chisel.  1  he  nose  should  be  heated  up  to  the  line,  BB,  in  Fig. 
51*,  and  then  cooled  as  far  as  CC.  The  final  cooling  is  done 
when  the  temper  color  at  the  tip  is  light  yellow. 

Project  31.    Cutting-Off  Tool.     (Plate  XXXI.) 

The  cutting-off  tool  is  used  for  making  a  narrow  groove  in 
work  on  a  lathe.  It  is  forged  with  the  blade  either  on  one  side 
or  in  the  center  of  the  stock.  The  easier  way  is  to  have  one 
side  of  the  blade  flush  with  the  side  of  the  tool,  as  in  this 
project. 

STEP  ONE. — Cut  the  stock  to  length,  and  center-punch  it, 
as  shown  at  1. 

STEP  Two. — Mark  with  a  fuller,  and  draw  out  the  part  A 
either  with  a  hand-hammer  on  the  rounded  edge  of  the  anvil 
or  with  the  trip-hammer.  The  hammering  should  be  done 
with  the  fullered  side  down,  in  the  same  manner  as  the  first 
step  in  forging  flat-jawed  tongs. 

STEP  THREE. — Taper  the  sides  of  the  blade  as  shown  at  3. 
Since  the  cutting  edge  of  this  tool  is  the  extreme  end,  it  must 
be  made  thicker  than  the  rest  of  the  blade,  so  that  it  will  have 
clearance. 

STEP  FOUR. — Cut  off  the  end  of  the  blade  with  a  hot  chisel, 
making  it  appear  as  at  4. 

In  tempering  this  tool  it  is  heated  to  the  line,  BB,  and 
cooled  to  the  line,  CC,  in  the  same  manner  as  the  round-nose 
tool.  The  temper  color  should  be  light  yellow. 

Project  32.    Threading  Tool.     (Plate  XXXII.) 
STEP  ONE. — Cut  and  mark  the  stock,  as  shown. 


Projects  30  and  31. 


Plate  XXXI. 


ROUND  NOSE  TOOL. 


5rockfx.xrroo.3ree,. 


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CUTTING  OFF  TOOL 

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126 


THREADING  TOOL  127 

STEP  Two. — Fuller  the  end,  as  at  2. 

STEP  THREE. — Draw-out  the  blade  with  a  set-hammer,  a 
top  fuller,  or  under  the  trip-hammer. 

STEP  FOUR. — Cut  off  the  end  with  a  hot  chisel.  The  cut- 
ting edge  is  generally  ground  by  the  person  using  the  tool. 
Harden  it  in  the  same  manner  as  the  cold  chisel,  tempering  it 
to  a  light  straw  color. 


Project  32. 


Plate  XXXII. 


THREADING    TOOL. 


Stock-  i"x  \"x  7  "tool  steel. 


© 


.. — ^ 


Use  2"  rop  and  bottom  fullers  Race 
center  of  fuller  on  center  punch  mark 


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Cut  off  along  doffed  line  and  grind   point 
to  OU'aiyie. 


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128 


SIDE  TOOL  129 

Project  33.    Side  Tool.     (Plate  XXXIII.) 

Side  tools,  or  side-finishing  tools,  are  shaped  as  shown  at 
4.  They  are  rnade  with  the  blade  at  either  the  right  or  the  left 
side,  and  are  called  right-  or  left-hand  side  tools.  The  blades 
may  be  bent.  Bent  side  tools  are  forged  in  the  same  manner 
as  the  others,  the  blade  being  bent  toward  the  shank  after- 
wards. 

STEP  ONE. — Cut  the  stock  to  length,  and  mark  it  as  shown. 

STEP  Two. — Make  a  fuller  mark  as  shown  at  2,  tipping  the 
fuller  so  that  the  groove  is  cut  deeper  at  one  side. 

STEP  THREE. — Draw-out  the  end  of  the  stock,  C,  at  the 
rounded  edge  of  the  anvil  with  a  heavy  hand-hammer,  the 
fullered  side  being  down.  Smooth  it  with  a  set-hammer. 
Trim  the  blade  with  a  hot  chisel  along  the  dotted  lines  shown 
at  3. 

STEP  FOUR. — Finish  the  tool  by  giving  the  top  edge  of  the 
blade  the  proper  offset.  To  do  this  it  should  be  placed  with 
the  flat  side  down  over  the  rounded  edge  of  the  anvil,  as  shown 
in  Fig.  A.  The  shoulder  of  the  blade  should  extend  about  }/% 
inch  beyond  the  outer  edge.  A  set-hammer  is  placed  on  the 
blade  close  to  the  shoulder  and  given  a  few  blows  with  a  sledge, 
to  produce  the  necessary  offset. 

In  hardening  this  tool  it  should  be  placed  in  the  fire  with 
the  cutting  edge  up,  in  order  to  avoid  overheating.  The  blade 
is  hardened  by  dipping  it  in  water,  as  shown  in  Fig.  B.  Only 
the  small  corner  of  the  blade,  D,  should  be  allowed  to  remain 
red-hot.  The  tool  is  removed  from  the  water,  quickly  pol- 
ished on  the  flat  side  of  the  blade,  and  tempered  to  a  light 
yellow  color.  The  entire  cutting  edge  should  be  uniform  in 
color.  If  this  is  not  the  case  and  it  is  blue  at  one  end  and 
straw  at  the  other,  the  blue  end  has  not  been  cooled  enough. 
The  tool  should  then  be  rehardened,  this  time  tipping  it  so 
that  the  end  of  the  blade  which  was  too  soft  will  be  deeper 
in  the  water. 


Project  33. 


Plate  XXXIII. 


SIDE  TOOL. 


Stock  -  t'x  I'x  8"  tool  steel. 


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A  c  i 


Use  i"  fuller. 


fig.  A. 


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130 


CROSS-PEEN   HAMMER  131 

Project  34.    Boring  Tool.    (Plate  XXXIV.) 

STEP  ONE. — Cut  the  stock  to  length,  and  mark  it  as  shown. 

STEP  Two. — Make  a  fuller  mark  as  shown  at  2. 

STEP  THREE. — Draw-out  for  the  thin  shank  either  under 
the  trip-hammer  or  at  the  rounded  edge  of  the  anvil  with  a 
sledge  or  heavy  hand-hammer.  The  length  of  this  shank  varies 
according  to  the  depth  of  the  hole  in  which  the  tool  is  to  be 
used. 

STEP  FOUR. — Bend  the  nose  as  shown.  Only  the  tip  of 
this  nose  need  be  hardened  and  tempered.  The  temper  color 
is  the  same  as  for  the  other  lathe  tools,  i.  e.,  light  yellow. 

It  is  sometimes  necessary  to  use  a  boring-tool  for  turning 
a  recess  having  sharp  corners.  In  this  case  the  nose  is  ham- 
mered flat  before  bending,  as  shown  in  Fig.  A.  It  is  then 
bent  up,  as  in  Fig.  B,  and  the  cutting  edge  ground  square. 

Project  35.     Cross-Peen  Hammer.     (Plate  XXXV.) 

In  forging  the  cross-peen  hammer  of  this  project  two  stu- 
dents should  work  together.  The  stock  used  should  be  8% 
inches  long,  giving  enough  material  for  two.  When  only  one 
hammer  is  required  the  stock  should  be  long  enough  to  work 
it  without  the  use  of  tongs.  With  handle  it-  should  weigh 
about  2^4  Ibs. 

STEP  ONE. — Mark  the  stock  as  shown  at  1  with  a  chisel 
and  a  center-punch. 

STEP  Two. — Bring  the  steel  slowly  to  a  yellow  heat,  and 
punch  it  with  an  eye-punch  similar  to  the  one  shown  in  Fig. 
52.  The  end  of  this  punch  is  shaped  somewhat  like  a  dull  cen- 
ter-punch, so  that  it  can  be  easily  driven  thru  the  stock  with- 
out cutting  out  too  much  material.  The  punch  should  be  re- 
moved from  the  hole  after  each  blow,  in  order  to  see  if  the 
hole  is  being  punched  straight.  This  also  cools  the  punch,  and 


Project  34. 


Plate  XXXIV. 


BORING  TOOL 


5tock-£"x  I  /  6§~  tool  5tee). 


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fig.  A 


132 


CR6SS-PEEN    HAMMER  133 

prevents  it  from  bending.  When  the  hole  has  been  punched 
nearly  thru  from  the  one  side,  the  punch  should  be  removed 
and  cooled.  Punching  is  then  finished  from  the  other  side. 


Fig.  52.     EYF.-PUNCH.  Fig.  53.    DRIFT-PIN. 

STEP  THREE. — Drive  a  tool-steel  drift-pin,  Fig.  53,  into  the 
hole.  The  bulging  sides  of  the  piece  should  then  be  hammered 
down  to  the  size  of  the  bar  with  a  sledge,  and  smoothed  with 
a  flatter.  Always  remove  the  drift-pin  before  reheating  the 
piece. 

STEP  FOUR. — Draw-out  the  face  end  to  the  form  shown. 

STEP  FIVE. — Trim  the  face  with  a  hot  chisel.  Drive  the 
drift-pin  in  from  each  side,  making  the  shape  of  the  eye  as 
shown.  Cut  off  the  stock  at  the  middle,  and  draw-out  the 
peen  end  in  the  same  manner  as  a  hand  chisel  is  forged,  either 
under  the  trip-hammer  or  with  a  heavy  hand-hammer.  Finish 
it  with  a  flatter. 

STEP  Six. — Finish  trimming  both  ends,  making  the  ham- 
mer appear  as  at  6. 

STEP  SEVEN. — When  cold,  grind  the  face  and  peen  slightly 
convex,  as  shown. 

For  hardening,  the  entire  hammer  is  slowly  heated  to  the 
refining  heat.  In  removing  it  from  the  fire,  one  jaw  of  a  pair 
of  tongs  should  be  inserted  in  the  eye.  The  face  is  hardened 
first  by  slowly  inserting  about  \l/2  inches  of  the  end  in  water,  as 


Project  35. 


Plate  XXXV. 


CROSS  PEI 

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134 


CROSS-PEEN    HAMMER  135 

was  done  with  the  cold  chisel.  When  it  has  cooled  enough, 
the  peen  is  hardened  in  the  same  manner,  care  being  taken  not 
to  cool  the  stock  around  the  eye.  While  cooling  the  peen, 
water  should  be  allowed  to  drip  on  the  center  of  the  face. 
This  prevents  the  colors  from  running  down  before  the  peen 
has  been  cooled  enough,  and  insures  a  uniformly  hardened  face. 
If  the  face  were  cooled  by  merely  dipping  it  in  water,  the  out- 
side edges  would  harden  faster  than  the  center  and  be  more 
likely  to  crack. 

After  cooling,  the  ends  are  polished  with  an  emery  brick, 
the  heat  around  the  eye  being  held  for  tempering.  Dark 
brown  is  a  good  temper  color  for  the  face,  and  brown  or  pur- 
ple for  the  peen.  If  the  desired  color  reaches  the  face  first, 
the  face  should  be  placed  in  water  until  the  proper  color  has 
reached  the  peen.  The  two  ends  are  then  dipped  alternately 
in  water.  This  allows  the  eye  to  cool  slowly,  making  it  tough. 

Project  36.     Small  Cross-Peen  Hammer.     (Plate  XXXVI.) 

This  hammer  is  forged  and  tempered  in  the  same  manner 
as  the  cross-peen  hammer  of  Project  35.  It  should  weigh 
when  finished  about  \l/±  pounds. 


Project  36. 


Plate  XXXVI. 


SMALL   CROSS   PCEN    HAMMER 


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Stock  - 1  x l"x 7*"to o I  sted . 

dTg/7/gA-  punch  ~y fMc/rtf  ¥\ 


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136 


SMALL  CROSS-PEEN   HAMMER 


137 


Project  37.     Ball-Peen  Hammer.     (Plate  XXXVII.) 

In  making  the  2-pound  ball-peen  hammer  shown,  a  piece 
of  1^-inch  square  tool  steel  6>^  inches  long  is  used.  This  is 
enough  stock  for  two  hammers ;  if  only  one  is  wanted  the 
stock  should  be  long  enough  to  work  without  using  tongs. 

STEP  ONE. — Mark  the  stock  as  shown  with  a  chisel  and  a 
center-punch. 

STEP  Two. — Flatten  out  the  end  as  shown  at  2.  If  this  is 
done  after  punching  the  hole,  the  hole  is  likely  to  become  too 
large. 

STEP  THREE. — Punch  the  hole  in  the  same  manner  as  in 
Project  35.  Drive  in  a  drift-pin,  and  hammer  down  the  sides 
as  shown  at  A  in  Fig.  54  until  they  are  straight. 

STEP  FOUR. — Roughly  shape  the  hammer  with  top-  and 
bottom-fullers,  as  shown  at  B  in  Fig.  54. 


Fig.  54. 

STEP  FIVE. — Round  the  body  of  the  hammer  at  the  rounded 
edge  of  the  anvil  with  a  top-fuller  and  a  set-hammer.  The 
body  should  taper  in  both  directions,  and  be  thicker  at  the 
center  than  at  the  edges. 

STEP   Six. — Cut  the  stock  at  the  chisel  mark  from   four 


Project  37. 


Plate  XXXVII. 


BALL  PE1EN  HAMMER. 


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5mck-li"xlix6j"  tool  steel. 


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er  by  qnndina. 


138 


HOT  EVE-CHISEL  139 

sides,  in  order  to  insure  a  square  end.  Draw-out  the  face, 
swage  it,  and  trim  it  with  a  hot  chisel.  The  peen  should  then 
be  cut  to  length,  and  the  corners  cut  off.  It  is  rounded  in  a 
bottom-swage.  The  reason  for  finishing  the  face  before  the 
peen  is  that  it  is  hard  to  hold  the  peen  with  a  pair  of  tongs. 

Grind  both  ends,  making  the  edges  of  the  face  slightly 
rounded,  to  prevent  the  hammer  from  marking  hot  material. 

This  hammer  is  hardened  and  tempered  in  the  same  man- 
ner as  the  cross-peen  hammer. 

Project  38.    Hot  Eye-Chisel.     (Plate  XXXV1I1.) 

If  only  one  hot  chisel  is  necessary,  it  may  be  forged  on  the 
end  of  a  bar  long  enough  to  handle  easily ;  but  if  two  are 
wanted,  the  stock  should  be  cut  10  inches  long. 

STEP  ONE. — Mark  the  stock  as  shown. 

STEP  Two. — Punch  the  hole  in  the  manner  described  in 
Project  35. 

STEP  THREE. — Draw-out  the  head  either  under  the  trip- 
hammer or  with  a  sledge.  Finish  it  with  a  flatter,  and  cut  of" 
the  end  with  a  hot  eye-chisel.  In  trimming  the  end  it  should 
be  made  slightly  convex. 

STEP  FOUR. — Make  fuller  marks,  as  shown  at  4,  with  y%- 
inch  top-  and  bottom- fullers.  The  stock  should  be  turned  over 
in  doing  this,  to  insure  a  uniform  depth  of  the  cuts. 

Punch  and  draw-out  the  head  for  a  chisel  at  the  other  end 
01  the  stock  in  the  same  manner.  Cut  the  stock  at  the  center 
from  two  sides  only,  in  order  to  have  the  blades  square  across 
the  ends  when  drawn-out. 

STEP  FIVE. — Draw-out  the  stock  for  the  blade  either  under 
the  trip-hammer  or  with  a  sledge,  and  smooth  it  with  a  flatter. 
When  trimmed  the  blade  is  hardened  and  tempered  to  a  blue 
color,  in  the  same  manner  as  the  hand  cold  chisel  of 
Project  26. 


Project  38. 


Plate  XXXVIII. 


HOT  EYE  CHISEL. 


.•5tock-  I* *  l±  A  10'  tool  afeel. 


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© 


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© 


140 


COLD  EYE-CHISEL  141 

Project  39.    Cold  Eye-Chisel.    (Plate  XXXIX.) 

For  a  cold  chisel  the  stock  is  marked,  the  eye  punched, 
and  the  head  drawn-out  and  finished  in  the  same  way  as  for 
the  hot  chisel.  After  cutting  the  stock  at  the  middle  the  blade 
is  drawn-out,  either  under  the  trip-hammer  or  with  a  sledge. 
Care  should  be  taken  in  doing  this  to  keep  the  sides  rounding, 
since  a  chisel  of  this  form  is  much  stronger  than  one  with 
straight  sides.  This  chisel  is  hardened  like  a  hand  chisel,  and 
tempered  to  a  brown  or  purple  color.  The  edge  should  be 
ground  slightly  convex. 


Project  39. 


Plate  XXXIX. 


COLD  EYE  CHISEL. 


Stock-  U"xli"x  9k"  tool  steel 


Chisel    Mark-? 


-is— I     [•—  -43--—         --p-   —  I*' 1 

L_.       _.*-      --4 


® 


® 


142 


GEOLOGIST'S  PICK  143 

Project  40.    Geologist's  Pick.     (Plate  XL.) 

This  pick,  which  is  intended  for  the  use  of  students  of 
geology,  should  weigh  about  2*/2  pounds  when  finished. 

STEP  ONE. — Mark  the  \%xl%-inc\\  stock  with  a  center- 
punch  and  chisel,  as  shown. 

STEP  Two. — Punch  the  hole  for  the  eye. 

STEP  THREE. — Insert  a  drift-pin  in  the  hole,  and  flatten 
the  sides.  With  a  hot  chisel  cut  the  stock  part  way  thru  at  a 
distance  of  T:V  inch  from  the  edge  of  the  hole,  on  both  sides 
of  the  eye.  These  cuts  should  be  finished  with  a  very  thin 
fuller,  or  with  a  hot  chisel  having  a  rounded  edge,  in  order 
to  make  the  bottom  of  the  cuts  round,  as  shown  at  3. 

The  material  should  then  be  cut  along  the  lines,  MN,  and 
OP.  The  material  cut  out  in  this  way  might  be  drawn-out 
instead,  but  this  would  be  difficult  without  a  beveled  setr 
hammer.  Cutting  it  out  is  somewhat  easier  and  quicker. 

STEP  FOUR. — Draw-out  the  end,  C,  under  the  trip-hammer 
to  the  size  shown. 

If  only  one  pick  is  being  made,  it  should  be  cut  off  of  the 
bar  at  the  chisel  mark  shown  at  1 ;  but  if  two  are  wanted,  the 
second  pick  is  started  in  the  same  manner  before  cutting.  The 
end,  D,  is  then  drawn-out  under  the  trip-hammer  to  the  form 
shown  at  5. 

STEP  FIVE. — Insert  the  drift-pin  in  the  eye,  and  smooth  the 
stock  around  it  with  a  set-hammer,  as  shown  in  Fig.  A.  Fin- 
ish the  head  with  a  set-hammer  and  flatter,  and  cut  it  to 
length  with  a  hot  chisel,  trimming  from  four  sides,  to  insure  a 
square  cut. 

STEP  Six. — Finish  the  pointed  end  with  a  flatter,  and  cut  it 
to  length.  The  face  and  point  are  then  ground,  hardened,  and 
tempered.  The  point  is  first  treated  in  the  same  manner  as 
the  cold  chisel,  being  tempered  to  a  dark  blue.  The  head  is 
then  heated  for  about  2  inches,  and  hardened  in  the  same 


Project  40. 


Plate  XL. 


GEOLOGIST'S   PICK.        3lock.rt-x,rroo,  5ree, 


Q 


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Fig.  A 


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144 


HAND   ROCK-DRILL  145 

manner.  It  is  tempered  to  a  brown  or  a  dark  straw  color.  In 
heating  the  head,  care  should  be  taken  to  prevent  the  heat  from 
flowing  back  and  softening  the  hardened  point.  This  may  be 
done  by  keeping  damp  coals  around  the  point. 

Project  41.    Hand  Rock-Drill.     (Plate  XLI.) 

STEP  ONE. — Cut  a  piece  of  24-inch  octagon  tool  steel  16 
inches  long.  Heat  the  end  and  draw  it  out,  making  it  about 
T3e  inch  thick,  as  shown  at  1.  The  hammering  should  be  done 
on  opposite  sides,  and  the  stock  allowed  to  widen  as  much 
as  possible. 

STEP  Two. — Trim  the  end  at  an  angle  with  a  hot  chisel,  as 
shown. 

STEP  THREE. — Finish  trimming  the  end  with  a  similar  cut, 
forming  the  cutting  edge  shown  at  3. 

STEP  FOUR. — Sharpen  the  edge  with  a  hand-hammer,  hold- 
ing the  stock  flat  on  the  face  of  the  anvil.  The  blows  should 
come  at  an  angle  of  45°,  to  force  the  metal  back;  and  the  drill 
should  be  rotated  about  the  cutting  edge,  in  order  to  make  it 
circular. 

After  sharpening  the  drill,  it  is  brought  to  the  refining  heat 
and  hardened  in  the  same  manner  as  a  cold  chisel.  The  tem- 
per color  should  be  a  dark  straw. 


Project  41. 


Plate  XLI. 


HAND  ROCK  DRILL. 


© 


© 


© 


Stock-  3-"x  16"  Octagonal  tool  steel. 


146 


MACHINE    ROCK-DRILL 


147 


Project  42.    Machine  Rock-Drill.  (  Plate  XLII.) 

STEP  ONE. — Cut  a  piece  of  24-inch  octagon  tool  steel  20 
inches  long. 

STEP  Two.— Upset  the  end  as  shown  at  2,  and  smooth  it 
with  a  flatter. 

STEP  THREE. — Make  small  grooves  along  four  sides  as 
shown  at  3  with  a  thin  fuller,  or  with  a  hot  chisel  having  a 
rounding  cutting  edge.  These  grooves  extend  back  2l/4  inches, 
and  are  made  for  the  purpose  of  guiding  or  holding  the  top 
and  bottom  V-fullers  in  place  when  fullering. 

STEP  FOUR.— Deepen  the  grooves  with  the  top  and  bottom 


Fig.  55. 

TOP  AND  BOTTOM 
V-FULLKRS. 


Fig.  56. 
WING  SWAGE. 


Fig.  57. 
DOLLY. 


V-fullers  shown  in  Fig  55.  The  stock  should  be  turned  dur- 
ing this  operation,  to  insure  uniformity  in  the  depth  of  the 
fuller  cuts. 


STEP  FIVE.  —  Make  the  sides,  or  wings,  of  the  drill  thinner 
and  wider,  using  a  bottom  sow,  or  wing  swage,  Fig.  56,  and 


Project  42. 


Plate  XLII. 


MACH.NL   ROCK  DRILL 


© 
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© 


5tock_,x20«0cragonaltool5teel. 


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148 


HUNTING  AXE  149 

a  square  set-hammer.  Trim  off  the  end  of  the  drill  with  a  very 
thin  hot  chisel,  making  it  square,  as  shown  at  5. 

STEP  Six.— Form  the  cutting  edges,  trimming  the  edges 
as  shown  at  6. 

STEP  SEVEN. — Finish  the  end  with  the  dolly  shown  in  Fig. 
57.  This  dolly  may  be  placed  with  its  head  resting  on  the 
anvil,  the  drill  point  being  driven  down  into  it  while  hot.  An- 
other method  is  to  hold  the  drill  across  the  face  of  the  anvil 
with  the  dolly  against  the  cutting  end,  and  then  strike  the  head 
of  the  dolly  with  a  backing-hammer.  If  a  very  keen  edge  is 
desired  on  the  drill,  it  should  be  filed  while  hot  with  a  square 
file. 

The  hardening  and  tempering  is  done  in  the  same  manner 
as  the  cold  chisel,  the  colors  being  drawn  to  a  dark  straw. 

Project  43.     Hunting  Axe.     (Plate  XLIII.) 

In  forging  the  hunting  axe  shown  in  the  accompanying  plate, 
two  students  should  work  together.  The  stock  used  should  be 
a  good  grade  of  tool  steel,  and  should  be  6^4  inches  long, 
giving  enough  material  for  two.  When  only  one  axe  is  re- 
quired the  stock  should  be  long  enough  to  work  it  without 
the  use  of  tongs. 

STEP  ONE. — Mark  the  stock  with  a  chisel  and  center-punch 
as  shown  at  I. 

STEP  Two. — Bring  to  a  yellow  heat,  and  punch  with  an 
eye-punch  similar  to  the  one  shown  in  Fig.  A.  The  center  of 
the  punch  being  held  directly  over  the  center-punch  mark  and 
the  narrow  edge  toward  the  blade  end  of  the  axe.  The  punch 
should  be  removed  from  the  hole  after  each  blow  in  order  to 
see  if  the  hole  is  being  punched  straight.  This  also  allows 
the  punch  to  cool,  which  prevents  it  from  bending.  Fine  coal, 
placed  in  the  hole,  will  prevent  the  punch  from  sticking. 
When  the  hole  has  been  punched  nearly  thru  from  one 


Project  43. 


Plate  XLIIT. 


HUNTING  AXE 


Stock:  i  X  a  Tool  Steel 


rir^ 


Cente-r  punch  MarK  with  chisel 


Drift  for  shaping  e,ye. 


150 


HUNTING  AXE  151 

side,  the  punch  should  be  removed  and  cooled.     Punching  is 
then  finished  from  the  other  side. 

STEP  THREE. — Drive  a  tool-steel  drift-pin  into  the  hole. 
The  bulging  sides  of  the  forging  should  then  be  hammered 
down  to  about  the  size  of  the  bar  with  a  sledge,  and  smoothed 
with  a  flatter.  Always  remove  the  drift-pin  before  reheating 
the  piece. 

Two  drift-pins  should  be  used,  the  first  one  driven  into  the 
hole  should  be  about  ^  of  a:i  inch  narrower  than  the  one 
used  for  finishing.  If  only  one  pin  is  used  it  should  not  be 
driven  in  so  that  the  hole  is  expanded  to  the  full  size  until 
the  axe  has  been  forged  to  nearly  its  correct  shape.  After 
the  drift-pin  has  been  driven  into  the  eye  as  described,  the 
portion  for  the  blade  is  then  drawn  out  with  a  power  hammer. 
As  the  blade  is  formed  the  eye  will  stretch.  To  avoid  a  cold 
shut  or  check  at  the  bottom  of  the  eye  the  drift-pin  should 
be  driven  in  to  take  up  the  space. 

The  blade  is  then  hammered  to  shape  with  a  heavy  hand- 
hammer  and  smoothed  with  a  flatter.  The  cutting  edge  is 
formed  in  the  same  manner  as  that  for  the  cold  eye-chisel, 
but  the  blade  is  not  trimmed  until  the  head  is  shaped  and  cut 
to  length.  If  only  one  axe  is  being  made,  it  is  cut  from  the 
bar  at  the  chisel  mark  and  the  head  is  drawn  to  size,  either 
with  a  power  or  sledge-hammer.  After  the  head  has  been 
cut  to  length  the  blade  is  trimmed  to  shape.  The  axe  should 
now  be  heated  to  a  full  red  and  annealed,  either  in  lime  or 
ashes.  When  cold  it  should  be  ground  on  an  emery  wheel 
and  finished  on  a  buffing  wheel. 

The  hardening  and  tempering  may  be  done  by  either  of  the 
following  methods : 

FIRST  METHOD. — The  axe  is  heated  very  slowly  to  the  re- 
fining heat  and  cooled  in  tepid  water.  The  temper  may  be 
drawn  by  placing  two  hot  iron  bars  on  either  side  of  it  at  the 
center.  The  proper  temper  colors  are:  For  the  blade,  dark 


152  TOOL   FORGING 

purple,  and  for  the  head,  blue.     When  these  appear  the  axe 
is  cooled  quickly  in  water. 

The  SECOND  METHOD  is  that  given  for  hardening  and  temper- 
ing the  cross-peen  hammer. 

Project  44.     Hunting  Knife.     (Plate  XLIV.) 

In  making  the  hunting  knife  shown,  a  piece  of  good  grade 
tool  steel  %"  x  %"  x  7^"  is  necessary.  A  longer  piece  may 
be  used  more  advantageously  since  the  tang  can  be  drawn 
down  without  the  use  of  tongs. 

STEP  ONE. — Mark  the  stock  on  the  edge  with  a  center- 
punch,  at  2y%"  from  the  end,  then  heat  it  slowly  to  a  yellow 
heat  and  form  the  shoulders  for  the  tang  with  a  square-edge 
set-hammer  as  shown  at  2,  Fig.  A.  After  the  shoulders  have 
been  formed,  draw  out  the  tang  either  with  a  power  or  hand- 
hammer. 

STEP  Two.— The  stock  at  the  shoulders  is  heated  and  they 
are  trued  up  by  placing  the  tang  loosely  between  the  jaws  of 
a  vise  as  shown  at  3,  and  hitting  on  the  end  of  the  piece  with 
the  hand-hammer. 

STEP  THREE. — The  stock  is  now  heated  and  bent  as  shown 
at  4,  and  the  lip,  C,  formed  with  a  square-edge  set-hammer. 
The  blade  is  then  drawn  out  with  a  two  and  one-half  pound 
hammer  to  a  width  of  l%"  at  C  and  lj£"  at  the  wide  end. 
The  cutting  edge  should  be  drawn  to  about  iV  °f  an  mcn 
thick.  The  blade  is  now  trimmed  with  a  hot  eye-chisel  along 
the  dotted  lines  shown  at  5.  The  knife  should  be  annealed 
in  lime  or  at  least  allowed  to  cool  slowly  before  grinding.  It 
is  now  filed  and  ground  to  the  desired  shape,  but  not  com- 
pletely finished.  The  cutting  edge  should  be  left  about  3V  °f 
an  inch  thick.  A  sharp  edge  will  warp  when  heated  for 
hardening. 


Project  44. 


Plate  XLIV. 


HUNTING  KNIFE  ,-      7"T     ,    q.      . 

StocK  .4X8  Tool    Steel 


153 


154  HUNTING  KNIFE 

HARDENING. — The  knife  is  heated  slowly  in  a  piece  of  pipe 
in  the  same  manner  as  the  tap.  When  it  has  reached  the 
refining  heat  it  is  dipped  in  fish  oil,  the  back  or  thick  edge 
first,  and  cooled  quickly. 

To  draw  the  temper,  the  knife  is  first  polished  with  a  buffing 
wheel  or  a  piece  of  emery  cloth,  it  is  then  held  over  the  flame 
of  the  fire  (the  blast  being  shut  off)  and  moved  backwards 
and  forwards  until  the  desired  color,  purple,  is  obtained,  then 
cooled  quickly  in  oil. 

A  bronze  guard  is  commonly  us.ed.  A  variety  of  handles 
are  suitable :  wood,  leather,  fiber,  leather  and  aluminum  discs 
or  washers.  When  leather  discs  are  used  the  end  of  the  tang 
is  forged  round,  and  a  thread  is  cut  on  it.  A  slotted  nut  is 
used  to  hold  the  washers,  which  have  been  glued  together, 
tight  against  the  guard.  The  handle  is  then  ground  to  shape 
on  the  emery  wheel. 


Elementary  Machine  Shop  Practice 

By  T.  J.  PALMATEER 
Instructor  in  Machine  Work,  Leland  Stanford,  Jr.,  University 

A  Combined  Textbook  and  Shop  Manual  for  Student  Use 

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